With the Iowa caucuses around the corner, progressive presidential hopefuls Sens. Bernie Sanders (I-Vt.) and Elizabeth Warren (D-Mass.) aren’t just clashing on the campaign trail — they’re also scrapping for endorsements on Capitol Hill.

House Democrats in the Congressional Progressive Caucus said the race for presidential endorsements has kicked into high gear in the closing weeks before the Feb. 4 Iowa caucuses.

Many downplay the significance of political endorsements, but campaigns see them as a way to show momentum and boost fundraising as the first voters in the nation prepare to head to the polls.

“It's crunch time,” said one undecided progressive freshman Democrat, who was heavily lobbied by both the Sanders and Warren camps this past week. “I've heard more about endorsing presidential candidates in the last three days than I've heard in the last three months.”