How might international issues play into the coming U.S. midterm elections? The conventional wisdom is that foreign policy rarely matters in congressional midterms, and will have no impact this November. In reality, however, even a cursory glance at American political history reveals that foreign policy and related issues can have an important impact on midterm elections. Despite the voluminous good work on closely associated topics by journalists, political scientists, and historians, I’m not aware of a single scholarly book or article that focuses on the relationship between foreign policy and U.S. midterm elections over multiple cycles. (Dear reader: If you know of one, please let me know.) Here’s a first crack at it.
With regard to the political impact of international issues, there seem to be four types of U.S. midterm elections:
Quagmire. These are congressional midterm elections where the president’s party is punished by voter dissatisfaction with some protracted and inconclusive military intervention overseas. Clear examples include 1950 (Korea), 1966 (Vietnam), and 2006 (Iraq). In each case, the president’s party lost a great many seats in Congress, and popular frustration with an ongoing war was one major reason why. The midterms of 1942 might also be included in this category, insofar as voter frustration with wartime inconveniences played into Democratic losses that fall.
Presidential affirmation. These are midterm elections where the president’s own party picks up seats in Congress in significant ways because of the president’s perceived strengths on foreign policy or national security issues. Such elections are surprisingly rare. The one obvious example is 2002, where Republicans broke the usual midterm pattern and gained seats in both houses, partly due to George W. Bush’s high support ratings on counterterrorism at that time. Even the midterms of 1962, immediately following the Cuban missile crisis, do not fit this pattern. At best, Democrats were able to use John F. Kennedy’s effective handling of the October missile crisis to negate potential Republican criticism. In the end, that November, Democrats picked up seats in the Senate, but lost them in the House.
Foreign policy as non-issue. These are congressional midterms where international issues are simply not politically important at all. Numerous midterm elections from the 19th and early 20th century would fall into this category, especially if trade and tariff policy is excluded.
Foreign policy as secondary but significant. Finally, these are midterm elections where foreign policy issues—though not of uppermost concern—can have an important impact at the margins. For example, during the 1994 midterm elections, the leading issues were indisputably domestic. But President Bill Clinton’s handling of a series of international security challenges—including Somalia, Haiti, and Bosnia—created political problems for numerous congressional Democrats at the ballot box that November.
Where does 2018 fit into the above categories?
This does not appear to be a quagmire election. Over the years, many American voters have grown tired of the war in Afghanistan. But the reduced U.S. presence, compared to its peak in 2011, has drawn the sting from that complaint. There is no evidence that frustration over Afghanistan is a significant political issue this fall. And with regard to the U.S.-backed campaign against ISIS, the Trump administration can point to significant success in rolling back the Islamic State at little cost in American lives. At the same time, President Donald Trump’s approval ratings on foreign policy, averaging in the low 40s, are not high enough to make a rare and ringing midterm presidential affirmation very likely. Nor are foreign policy issues, per se, of primary concern this November. For example, the killing of Saudi journalist Jamal Khashoggi—while of dramatic importance to U.S.-Saudi relations and beyond—is not a major point of contention in current U.S. midterm elections. The question this electoral season is whether the place of international issues overall lies in category 3 (non-issue) or category 4 (secondary but significant). I would suggest category 4, secondary but significant, and here’s why.
First, ever since the U.S. assumed a global strategic role in the 1940s, any president’s handling of this role has been a significant issue politically, including in midterm elections, even if only in the background. The question of whether specific presidents are viewed as competent or incompetent in managing America’s continuing international commitments is an inescapable political issue for both parties, and is bound up with broader perceptions of presidential leadership.
Second, beginning with his run for the White House, President Trump—specifically—has bundled together what might be called transnational issues, with conventional foreign policy ones, to create a distinctly nationalist political platform emphasizing the relationships between trade, immigration, counterterrorism, allied burden-sharing, and foreign policy. His political opponents have no choice but to address this issue bundling, whether they agree with it or not.
Third, although the very top issues this November—health care, the economy, and Supreme Court appointments, to name three—are undoubtedly domestic, there is considerable polling evidence that foreign policy is of some real interest to voters right now. According to a September 2018 poll from NBC News and the Wall Street Journal, 66% of voters say that “foreign policy and terrorism” is a very important issue in determining how they will vote. Republicans are even likelier than Democrats to consider terrorism a “very important issue.” And when factoring in other transnational issues such as trade and immigration, along with broader perceptions of presidential leadership, the political significance of U.S. international policy becomes more fully apparent.
According to the Pew Research Center, trade policy is a “very important issue” for 55% of voters approaching the November elections. Moreover, a number of Democratic congressional candidates in both agricultural and Rust Belt states have treated it as such, focusing in on concerns about trade disputes with U.S. allies. Immigration policy for its part is undoubtedly a major issue this fall, with the two parties highly polarized. A survey recently conducted by the Washington Post with the Schar School at George Mason University indicated that 52% of voters describe immigration as “extremely important” in determining their vote. Indeed, 17% of Republicans say that immigration is the single most important issue for them electorally. President Trump’s leadership style is also under judgement this fall, and that necessarily includes his foreign policy leadership as part of his overall approach. A solid majority of American voters regularly indicates that Trump himself is a leading issue for them.
Are there indications that international issues broadly defined favor one party over the other this November?
Numerous observers have argued that President Trump’s foreign policy approach will act as a liability for Republicans on November 6. Perhaps, they think it should. But in reality, the evidence on this score is mixed. Polls taken by Quinnipiac University and the Pew Research Center in August and September, respectively, showed Democrats with a 3-to-8 point lead over Republicans on foreign policy issues. These polls, along with others by NBC News and the Wall Street Journal, further showed Democrats with a 4-to-10 point lead on the issue of immigration.
Yet, when the question is posed as one of illegal immigration or border security, in these same polls, Republicans take the lead over Democrats by a margin of anywhere from 3-to-11 points. The White House is certainly aware of this, and looks to be emphasizing it in the final days of the midterm election season. National security, according to the Quinnipiac poll, also continues to be a strong issue for Republicans, by a margin of 8 points. And when asked which party is now preferred on “protecting America’s interest on trade issues,” according to NBC News, voters prefer Republicans over Democrats by a margin of anywhere from 8-to-17 points.
One notable foreign policy achievement in recent weeks was the successful renegotiation of NAFTA with Canada and Mexico. To reach this point, all three countries made significant concessions. For those congressional Republicans nervous about their own re-election as well as the president’s trade policies, this agreement could hardly come too soon. Critics will note that the new agreement only removes uncertainties originally introduced by Trump himself. Still, the president ran and won the 2016 election on a platform clearly critical of NAFTA, and in pressing for its revision did what he said he would do. For Midwest farmers, U.S. exporters, congressional Republicans, America’s allies, and U.S. consumers as a whole, the conclusion of this revised agreement with two of America’s largest trading partners should be considered a success. The administration can now reasonably point to this agreement as evidence that the president does not look to dismantle international trade with allies per se, but is open to compromise involving revision of existing arrangements, with a growing common focus on the greater challenge from China.
Viewed altogether, while international policy and related issues such as trade, immigration, and presidential foreign policy leadership may not be the primary driver of voting this season, they are still quite significant. November 6 will see a number of tight races to determine party control of both the Senate and the House. And as one seasoned observer notes, “In these tight races, everything matters.” Of course, Republicans may very well lose control of the House of Representatives, for reasons having little to do with foreign policy. But what polling evidence does exist on these subjects suggests that international issues taken together will not hurt congressional Republicans as badly as once believed. In effect, particularly with the conclusion of the new NAFTA agreement, the administration may have removed foreign policy as a potentially damaging issue heading into the coming midterms. For Republicans interested in winning elections under current circumstances, this in itself counts as a kind of relief.
Finally, how might the midterm election results impact U.S. foreign policy?
Foreign observers—whether U.S. allies or adversaries—are paying close attention to these midterm elections, in the knowledge that voting results may have some impact on American foreign policy. If Democrats take control of the House, for example, this will of course increase their ability through committee majorities to hold hearings, exercise oversight, and generally hold the president’s feet to the fire. This could complicate ongoing U.S. diplomatic negotiations in some cases. It could even lead to impeachment proceedings, depending upon the final outcome of Robert Mueller’s special counsel investigation.
One germane foreign policy question in 2019 will be whether congressional Democrats, possibly in control of the House, will support the new trade agreement with Canada and Mexico. Ironically, in these negotiations, President Trump delivered a number of policy revisions called for by organized labor and progressives over the years. But of course congressional Democrats are also under intense pressure to oppose the Trump administration as a whole. It remains to be seen whether sufficient numbers of congressional Democrats can bring themselves to support a revised NAFTA concluded by this particular president.
On the GOP side, given the retirement of Senator Bob Corker (R-TN) and the death of John McCain (R-AZ), congressional Republicans face new leadership challenges on foreign policy and national security issues. In the Senate, Senator Lindsey Graham (R-SC) now assumes the mantle for the perspective once represented by McCain. Senator Marco Rubio (R-FL) has carved out a strong role on key issues such as U.S. policy toward Cuba and Venezuela. Senator Tom Cotton (R-AR) has become an articulate proponent for the nationalist point of view. And Senator Rand Paul (R-KY) continues to be a prominent champion for libertarians. Interestingly, President Trump appears to have developed surprisingly good working relationships with all four of these senators—Graham, Rubio, Cotton, and Paul—regardless of their ideological differences. In the House, look for current freshman Representative Mike Gallagher (R-WI) to continue his rise as a leading Republican voice on national security matters.
Observers should note that in the American foreign policy system, as it has evolved since the 1940s, all presidents tend to assume remarkable leeway in exercising executive authority, regardless of congressional majorities. Significant midterm losses can and do often act as a calibration or check on overall presidential agendas. But in foreign policy, at least, recent presidents have tended to react to midterm losses with a forceful determination to continue on their settled course. This was certainly true of George W. Bush in 2006-07 with regard to Iraq. It was also true of Barack Obama in 2010-11 and 2014-15, for example in nuclear arms control negotiations with Iran.
Analysts should therefore consider the possibility that President Trump will react to any midterm losses, not by abandoning his overall foreign policy direction, but by maintaining its basic continuity alongside tactical adaptations. Indeed, the conclusion of midterm election season might very well free up the president to pursue foreign policy directions he prefers in any case. This would be consistent with historical precedent. In an excellent study of past presidential elections and U.S. foreign policy, political scientist Kurt Taylor Gaubatz points out that presidents tend to hew closer to the median voter on key international issues before re-election. If this logic holds true for midterm elections as well, then with or without GOP losses, Trump may take the midterms’ conclusion as reason to forge ahead on foreign policy and defy his critics—just as recent presidents have done.
 On presidential elections and the prospect of U.S. military intervention, Kurt Taylor Gaubatz, Elections and War: The Electoral Incentive in the Democratic Politics of War and Peace (Stanford, CA: Stanford University Press, 1999) is indispensable. A good overall study of U.S. midterm elections is Andrew Busch, Horses in Midstream: U.S. Midterm Elections and Their Consequences (Pittsburgh, PA: University of Pittsburgh Press, 1999).
 Timothy McKeown, “The Cuban Missile Crisis and Politics as Usual,” Journal of Politics 62:1 (February 2000), 70-87; and Thomas Paterson and William Brophy, “October Missiles and November Elections: The Cuban Missile Crisis and American Politics, 1962,” Journal of American History 73:1 (June 1986), 87-119.
 Trevor Thrall, “Will Trump’s foreign policy matter for the midterms?” The Hill, August 9, 2018.
AEI Political Report: A Monthly Poll Compilation 14:9 (October 2018), p. 3.
 Michael Collins, “In the farm belt and manufacturing hubs, tariffs and trade turn into election issues,” USA Today, October 9, 2018.
 Scott Clement and Dan Balz, “Survey of battleground House districts shows Democrats with narrow edge,” Washington Post, October 8, 2018.
 Natasha Korecki, “Poll: Trump’s overseas ‘chaos’ gives Democrats and edge in midterms,” Politico, August 8, 2018.
 Julie Hirschfield Davis, “GOP Finds an Unexpectedly Potent Line of Attack: Immigration,” New York Times, October 14, 2018. This development was accurately predicted months ago by Freddy Gray, “Trump is ‘vice-signaling’ over immigration – and it’s going to work,” The Spectator, June 19, 2018.
AEI Political Report, pp. 5-6. A 17-point advantage for the GOP on issues of trade was noted by Janet Hook, “Interest in Midterm Surges, Along With Trump Approval Rating,” Wall Street Journal, October 21, 2018.
 Robert Fife and Adrian Morrow, “Canada, U.S. reach tentative NAFTA deal; Trump approves pact,” The Globe and Mail, October 1, 2018; Edward Helmore, “Global stocks soar on U.S.-Mexico trade breakthrough as Canada is sidelined,” The Guardian, August 28, 2018; and Jacob Schlesinger, Kim Mackrael and Vivian Salama, “U.S. and Canada Reach NAFTA Deal,” Wall Street Journal, October 1, 2018.
 Justin Sink, “Trump’s New NAFTA Deal Comes Just in Time for the Midterms,” Bloomberg, October 1, 2018; and Ben White, “Trump’s trade wars start biting GOP ahead of midterms,” Politico, September 24, 2018.
 James Pethokoukis, “Trump’s new trade deal with Canada and Mexico fixes what he broke,” NBC Think, October 2, 2018.
 Aaron Back, “New Trade Deal Sets Stage for Contest with China,” Wall Street Journal, October 1, 2018.
 Collins, “Tariffs and trade turn into election issues.”
 Robbie Gramer, “Will Republicans Lose Their Majority in Congress? Ask Pyongyang,” Foreign Policy, October 8, 2018; and David Ignatius, “Trump’s friends overseas are very, very nervous about the midterms,” Washington Post, August 21, 2018.
 Schlesinger, Mackrael and Salama, “U.S. and Canada Reach NAFTA Deal.”
 Marc Caputo, “Trump’s team gets payback for Rubio on Venezuelan assassination plot,” Politico, May 22, 2018; Eliana Johnson, “Trump connects with Rand ‘at gut level’,” Politico, August 8, 2018; John McCormack, “The Neo-Trumper,” Weekly Standard, June 22, 2018; and Jason Willick, “A Foreign Policy for ‘Jacksonian America’,” Wall Street Journal, December 8, 2017.
 Jamie Fly, “Do Not Look for Foreign Policy Change,” German Marshall Fund, October 23, 2018.
 Gaubatz, Elections and War, 49-50, 78-79, 126-27, 142-45.