More House seats are opening up as more members announce their upcoming departures. Republican Harriet Hageman says she's running for Senate, winning President Donald Trump's endorsement swiftly after making her intentions public. Republican Elise Stefanik had already said she was running for governor of New York, but now she's ended that bid — and also says she won't return to the House. Midterm elections are historically tough on the party of the sitting president. And Republicans only have a razor-thin margin in the House.
