A strong economy may be less of an advantage for Mr. Trump than for previous incumbents. Partisanship now shapes perceptions of the economy more than at any other time in decades. Nearly all the increased satisfaction with the economy is attributable to a 60-point rise among Republicans since 2016.

In addition, the political landscape has changed since James Carville’s famous “It’s the economy, stupid” maxim in 1992. Divisions over culture and identity have become more salient across liberal democracies. A good case can be made that Candidate Trump’s pledge to get tough on immigration and build a border wall had a greater effect on the 2016 election than his stance on trade and other economic issues.

Any other president presiding over vigorous job creation and sustained full employment would enjoy robust approval. But Mr. Trump’s job approval lags far behind his rating on the economy. Only 37% of registered voters think he is honest. While about half the electorate approves of his acquittal in the impeachment trial, only 40% believe it cleared him of wrongdoing in the Ukraine matter. Many Americans who give Mr. Trump credit for accomplishments at home and abroad disapprove of his conduct and of the rhetoric that divides the country, even as it arouses his well-tended base. Some of these people could be persuaded to vote against him—if the alternative is attractive.