When House Speaker Nancy Pelosi announced the formal opening of an impeachment inquiry into President Donald Trump on Tuesday, she did so with the backing of nearly two-thirds of her caucus.

But while members in safe Democratic seats have pushed for impeachment proceedings for months, it took the support of several swing-seat Democrats who represent districts Trump carried in 2016 to convince the speaker to move.

This page will keep track of the Democratic representatives who have come out in favor of some sort of impeachment proceeding, and will update if more come on board.

To impeach a president and send to the Senate for a trial, 218 representatives in the House must vote in favor of impeachment. So far, 216 Democratic representatives and one independent have signaled their openness to some kind of impeachment inquiry, putting the total number very close to a majority.

See the latest on impeachment proceedings from NBC News.