They can’t stop President Donald Trump’s nominees to the cabinet or Supreme Court, but Senate Democrats’ votes are being closely watched by members of both parties and will lay the foundation of their voting record under Trump.

There are 48 Democrats in the Senate, eight of whom are up for re-election next year in states that Trump won.

For lawmakers facing tough re-election fights, a vote for a nominee can be portrayed as a sign of independence from their party to the crossovers they’ll need to win. Not surprisingly, North Dakota Sen. Heidi Heitkamp and West Virginia Sen. Joe Manchin have been some of the most reliable votes for Trump nominees.

But for Democrats eyeing a challenge to Trump in 2020, a long string of votes against Trump’s nominees can be touted as evidence of their commitment to oppose the president from day one. New York Sen. Kirsten Gillibrand, seen as a top-tier White House contender, has voted against all but one of his nominees.

For others, their votes are determined by the nominee and position in question. Across the board, however, Democrats seem to have stepped up their opposition to Trump and his nominees this week, as reflected in the growing number of “nay” votes.

NBC News will update this list as the Senate takes further confirmation votes.