The 2018 midterm elections on Tuesday, Nov. 6, will give President Trump his first chance to defend the Republican Party's Senate and House majorities. Already, however, several Republicans in Congress have announced they won't be running for re-election. Here's our running list.

Not running for re-election

Rep. Charlie Dent, R-Pa.

  • Dent, a centrist Republican, announced in September that he'd decided against running for re-election after consulting with family and advisers. Pennsylvania state Rep. Justin Simmons had announced he would challenge Dent in the primary.

Related: Republicans fear 'flood' of centrist retirements ahead of 2018 elections

Rep. Dave Reichert, R-Wash.

  • Reichert faced tense townhall crowds during the August recess, and announced upon returning in September that he had decided "this will be my last term." A number of Democrats were already preparing to try to challenge him. The Democratic Congressional Campaign Committee celebrated afterward that "clearly, Congressman Reichert saw the writing on the wall."

Rep. Ileana Ros-Lehtinen, R-Fla.

  • Cuban-American and the first Hispanic woman elected to Congress, Ros-Lehtinen announced back in April 2017 that she will retire at the end of her current term. Speaker Paul Ryan afterward called her "a force." She has clashed with President Trump on transgender issues, deportations, and his travel ban.

Rep. Dave Trott, R-Mich.

  • A centrist Republican who has criticized President Trump, Trott announced in September after some speculation that he would not seek a third term.

Updates will be added.