Sen. Susan CollinsSusan Margaret CollinsThe Hill's Morning Report — Russia furor grips Washington Overnight Health Care: Novartis pulls back on drug price hikes | House Dems launch Medicare for All caucus | Trump officials pushing ahead on Medicaid work requirements Senate panel to vote next week on banning 'gag clauses' in pharmacy contracts MORE (R-Maine), speaking from the Republican National Convention, on Tuesday said she may vote for Democrat Hillary ClintonHillary Diane Rodham ClintonBernie Sanders: Trump 'so tough' on child separations but not on Putin Anti-Trump protests outside White House continue into fifth night Opera singers perform outside White House during fourth day of protests MORE for president.

"I have always supported the nominee of my party, my entire life, and it is extremely unlikely that I would vote for Hillary Clinton, but I'm not completely closing the door, but it is extremely unlikely," Collins told CNN.

"It is more likely that I would decide to write in a candidate or choose another approach."

Collins made clear that she also isn't ruling out voting for presumptive GOP nominee Donald TrumpDonald John TrumpWSJ: Trump ignored advice to confront Putin over indictments Trump hotel charging Sean Spicer ,000 as book party venue Bernie Sanders: Trump 'so tough' on child separations but not on Putin MORE.

"We still have a ways to go, and I do believe in redemption," she said.

"And there is a chance that he will make amends, start acting more presidential and come up with a positive agenda for our country."

Collins, who has criticized Trump in the past, said previously her decision on whether to endorse Trump may depend on who he chooses as a running mate.

"This evolves daily. There are surprises daily. And I'm going to see what happens at the convention," Collins said earlier.