Sen. Susan Collins, R-Maine, said Sunday she was prepared to live with the consequences of supporting Supreme Court Justice Brett Kavanaugh's confirmation, firing a warning shot to potential Democratic challenger Susan Rice.

"I'm going to do what I think is right. That's what I owe my constituents," Collins said during an interview with CNN'S "State of the Union." "As far as Susan Rice is concerned, her family has a home in Maine, but she doesn't live in the state of Maine. Everybody knows that."

Rice, who served former President Barack Obama as U.S. ambassador to the United States, hinted last week she may mount a Senate campaign to represent Maine when Collins is up for re-election in 2020.

"The irony is that back in 2009 when she was nominated to be ambassador to the U.N., she came to me, even though I did not know her back then at all, and pleaded with me to introduce her before the committee, which I was happy to do because her family had links to the state of Maine," Collins said of Rice's Senate Foreign Relations Committee hearings ahead of being confirmed to the diplomatic post.