Republicans hold a commanding House advantage with their biggest majority since 1931. Democrats are expected to cut into that edge next month, and with Donald Trump's declining presidential fortunes, they are hoping to capture House control. They'd need to pick up 30 seats, a gain they've achieved only once since the mid-1970s.
A look at the House landscape:
Current party breakdown: 247 Republicans, 188 Democrats. Two of those Democratic seats are vacant after the resignation of Pennsylvania Rep. Chaka Fattah following his conviction on federal corruption charges and the death of Hawaii Rep. Mark Takai in July. The one Republican vacancy was created by the resignation of Kentucky Rep. Ed Whitfield.
Some incumbents to watch:
—Four-term Rep. Mike Coffman, R-Colo., has run ads criticizing Donald Trump in this swing district as he tries to hold off Democrat Morgan Carroll, a state senator .
—First-term Rep. Brad Ashford, D-Neb., represents a Republican-leaning district and is locked in a close race with retired Brig. Gen. Don Bacon.
—Two-term Rep. Robert Dold, R-Ill., faces a rematch against former Democratic Rep. Brad Schneider in a state that will be tough for Republicans.
—Seven-term Rep. Scott Garrett, R-N.J., is in a challenging race in his suburban district against Josh Gottheimer, a former speechwriter for President Bill Clinton who's raised plenty of money.
—Twelve-term Rep. John Mica, R-Fla., is seeking re-election in a reconfigured district against Democrat Stephanie Murphy, a political newcomer for whom national Democrats are pumping in lots of cash.
The November winners will meet on Jan. 3, 2017, when the 115th Congress begins its two-year session. Lawmakers will vote on speaker and other members of the leadership.