It turns out that heckling NATO, imposing tariffs on allies and cozying up to Russia don’t do much for a president’s approval ratings. After Trump’s whirlwind European tour, his bizarre press conference with Russian president Vladimir Putin, and weeks of trade skirmishing with Europe, a recent Quinnipiac poll found that just 38 percent  of Americans approve of Trump’s handling of foreign policy. In fact, 38 percent is about Trump’s average foreign policy approval since taking office and promising to put “America First.”

As we head toward the midterm elections, these figures should have Trump and the Republicans worried. Some might argue that foreign policy won’t matter at the polls and that the state of the economy and other domestic issues play bigger roles at election time. But there are several reasons to think this time will be different.

First, foreign policy matters more to Americans thanks to Trump. The genius of Trump’s “America First” slogan was the way it allowed Trump to connect foreign and domestic politics under a single populist and nationalist banner. When Trump says he’s protecting American workers, he could be talking about tax cuts, illegal immigration, “horrible trade deals,” or terrorism. Trump’s America First strategy has blurred much of the historical difference between foreign policy and domestic policy. Trump has also spent a lot more time talking about trade and immigration than his predecessors. All of this makes foreign policy more important moving forward.

Unfortunately for Trump and the Republicans, Trump’s foreign policies have been historically unpopular. Not only does Trump suffer lower approval for his handling of foreign policy than all presidents back to Ronald Reagan, but majorities of Americans oppose Trump’s calling card issues. Fifty-eight percent oppose building a wall along the Mexican border and 67 percent think that illegal immigrants currently living in the United States should eventually be allowed to apply for citizenship. Twice as many Americans (49 percent) think raising tariffs will hurt the economy as think it will help (25 percent), and by a margin of 63 percent to 25 percent, Americans think maintaining good relationships with allies is more important than imposing tariffs to protect American industries. More Americans think Trump has weakened the United States’ position as a world leader (51 percent) than think he has strengthened it (35 percent).

Foreign policy is also a more important determinant of overall presidential approval than many realize. Many observers assume that unless there is a war at election time most people pay too little attention to foreign affairs for it to affect their votes. But even though the impact of foreign policy is most obvious during a war or international crisis, it plays a key role in shaping the general narrative of a president’s performance while in office. One analysis, for example, found that public approval of the president’s handling of foreign policy has a larger impact on his overall approval rating than does his handling of the economy. 

Given how low Trump’s foreign policy ratings have been, it is no surprise that President Trump’s general approval numbers have also been historically low, averaging just 39 percent according to Gallup. In fact, Trump has fared worse in terms of public approval in his first two years in officethan did every president since Harry Truman.

And this, in turn, is very likely to cause Trump and the Republicans trouble at the midterms. Research suggests that Trump’s current 41 percent approval rating historically would typically result in about an 8‑point national advantage in voting for Democrats. Trump’s performance to date certainly has Democrats already motivated — 61 percent of Democratic voters say their vote in November will be “against Trump,” compared with 51 percent of Republicans who voted “against Obama” in 2014. The end result is unlikely to be pretty for Republicans. Looking at data from each president’s first midterm elections going back to 1946, the four presidents who did not enjoy a net-positive approval rating saw their party lose an average of 49 seats in the House and 6.5 seats in the Senate.

It is still too early to make predictions, but one thing seems clear: Trump will remain a wildcard with a penchant for dominating the news cycle. Given how central people’s views of Trump are to the elections, a last-minute crisis – real or self-imposed – could play an important role in close races this fall. Between saber rattling with Iran, immigration negotiations with Congress, unresolved business with North Korea, and trade battles with China, Trump has plenty of opportunities to make sure foreign policy is front and center this fall.