Congress is back in session so of course impeachment of President Donald Trump is top of mind.Speaker Nancy Pelosi is speaking at a press conference Tuesday evening, after meeting with House Democrats to discuss the possibility of holding a vote on the ongoing impeachment inquiry against President Trump.Republicans have argued that the impeachment inquiry is illegitimate because the full House has not voted to formally begin an investigation. The inquiry is currently being carried out by several committees. The White House counsel has also cited the lack of a full vote as a reason that the White House is not cooperating with the inquiry. A formal House vote is not a step that is required by the Constitution to begin an impeachment inquiry, although previous inquiries have started with such a vote.The vote would force Democrats and Republicans to go on the record for their support, or lack thereof, for an impeachment inquiry. Some freshmen Democrats who flipped Republican seats in 2018 have been hesitant to come out in support for an impeachment inquiry, as it could be politically unpopular in their districts. However, such a vote would also force vulnerable Republicans to either align themselves with the president or risk alienating the Republican base.