Explore Gallup's research.
Competing factors for the midterms are presidential approval, which would imply GOP losses, and economic sentiment, which would suggest GOP gains.
Democrats looking for a midterm message beyond opposing Donald Trump have a number of traditional Democratic issues to choose from. Republicans' power issue with core Republicans is immigration.
Midterm elections are notoriously perilous for the president's party, and Trump's approval rating only makes matters worse. Can he produce another surprise?