November prospects

President Donald Trump’s job approval ratings have risen a lot in the last month. Many Republicans think this improvement may be good enough to save them from an electoral wipeout this fall. That may yet happen, but the improvements so far are not good enough to remove the GOP from danger.

Political analysts look at two measures to assess how a party will do in a midterm election: presidential job approval and the generic congressional ballot. History teaches us that most midterms are referenda on the sitting president, and a party’s performance usually correlates strongly with the president’s approval ratings. Presidents whose job approval is at or below 40 percent near Election Day usually see their party lose a large number of seats in Congress and state legislatures.

The congressional generic ballot assesses the public mood regarding which party voters favor. It’s not an ironclad test: Individuals do matter, and even in so-called “wave” elections (where one party loses in a landslide) popular incumbents from the losing party will retain their seats. The general, pre-Trump rule of thumb was that Democrats need to win the generic ballot by about 8 percent to win a majority of House seats.

Both measures have improved for Republicans since mid-December. Trump had only a 37 percent approval rating on Dec. 16; today he is at 42 percent (both figures taken from the RealClearPolitics.com poll average). The generic ballot has also moved in the Republicans’ favor, from a 13-point deficit in mid-December to only a 7-point deficit today.

Even a small increase in Trump’s approval rating could be the difference between GOP control and Speaker Nancy Pelosi.

The good news for Republicans is that these movements have largely occurred among Republicans and independents. The president’s job approval rating has improved by between 2 and 23 points in the four polls that have comparable figures for mid-December and today. That averages to a 7-point gain, from 29.5 percent to 36.5 percent. Trump is still not well-liked, but he seems to be no longer hated by a significant number of swing voters.

This gain among independents has occurred in the generic ballot too. Two polls with comparable figures show the GOP gaining significantly from December: Both show dramatic gains among independents. Swing voters who are warming to Trump seem to be warming to his party as well.

These polls would be good news for Republican candidates in the Senate. Democrats are defending five seats in states that Trump won by between 19 and 41 points (Montana, North Dakota, Missouri, Indiana, and West Virginia). They are defending another five in states that Trump won by between 2 and 8 points (Wisconsin, Michigan, Ohio, Florida, and Pennsylvania). The generic ballot shows that this year’s congressional vote is extremely highly correlated to 2016’s presidential ballot. If Trump continues to do just well enough that the vast majority of people who voted for him will also vote for a Republican, then Republicans look poised to make significant gains in the Senate.

The same cannot be said, however, for Republicans running for the House. The GOP has a 24-seat majority right now; Hillary Clinton won 23 of those districts. Unless Trump starts to win back some of the former Republicans who voted for her, all of these seats are under threat. As things stand now, Republicans would lose almost all of them in November, putting the House majority at risk even though the Democrats are a bit short of their rule-of-thumb 8-point lead.

Trump can do a lot to help his party cut its losses and hold onto House control. Even a small increase in his approval rating, from 42 to 44 or 45 percent, could be the difference between GOP control and Speaker Nancy Pelosi. Based on the improvement since December, he needs to keep on doing what he’s doing.