Balance of power in Congress on the line in Tuesday’s midterm election

Voters will decide Tuesday which party controls Congress for the final two years of President Donald Trump’s term.

All 435 seats in the U.S. House of Representatives and 35 seats in the U.S. Senate are on the ballot this Election Day. Republicans currently control both chambers.

VOTER GUIDE: Everything you need to know for the November general election

Republicans have a 219-214 edge in the House, with two vacancies. In the Senate, Republicans hold 53 seats, while Democrats and the independents who caucus with them hold 47.

Most Senate races involve seats whose six-year terms are expiring; that’s 33 seats. Meanwh...