The congresswoman from Hawaii has offered her “full support” to the former vice president.
“It's going to be a landslide,” one said Monday while waiting to hear Trump speak to an adoring throng in New Hampshire.
A poor showing on Tuesday could force some candidates to rethink their campaigns.
The 2016 Democratic nominee is accused of spreading lies about Gabbard to harm her 2020 presidential campaign.
The 2020 candidate, who voted "present" on the articles against Trump, said impeaching him will boost his chance of reelection.
Abercrombie, a Democrat who also served nine terms in the House, said Gabbard has proved incapable of juggling her congressional duties and her bid for president.
Lawmakers leaned on the Founding Father to defend their impeachment votes — whatever they were.
The congresswoman from Hawaii, a 2020 presidential hopeful, was among a handful of House Democrats who did not vote to impeach Trump.
The presidential candidate threatened to skip the October debate before reversing course and showing up.
Will Ferrell's Tom Steyer, meanwhile, is running because "it's fun and it gets me out of the house."