Susan Rice, who was President Barack Obama's national security adviser, caused a stir Friday afternoon when she tweeted "Me" when another former Obama official asked who could challenge Sen. Susan Collins in 2020.
The short tweet -- which came less than an hour after Collins, a Maine Republican, announced she would vote to confirm Brett Kavanaugh to the Supreme Court -- caught national and state Democrats by surprise.
Rice tweeted a little later that she was "not making any announcements" but was "deeply disappointed" by Collins' vote.
Rice has a home in Maine, a source said, and her family has ties to the state: Her mother, an education policy expert who was instrumental in the creation of the Pell Grant, was born there.
Rice's "Me" tweet was a response to another Obama-era official, Jen Psaki, tweeting: "who wants to run for Senate in Maine? there will be an army of supporters with you."
In the follow-up tweet, Rice said: "Many thanks for the encourgement. I'm not making any announcements. Like so many Americans, I am deeply disappointed in Senator Collins' vote for Kavanaugh. Maine and America deserve better."
Rice was one of several Democrats on Friday openly discussing the possibility of running against Collins in a presidential swing state that has a history of political independence.
Rice was Obama's ambassador to the United Nations, and later his national security adviser. Since departing the administration, she has been a visiting fellow at American University's School of International Service and was appointed to the board of directors of Netflix.