Progressive activist Ralph Nader attacked Sen. Jeff Flake for voting to advance Brett Kavanaugh's nomination to serve on the Supreme Court, saying the Arizona Republican "just lowered himself into Trump's swamp.'

The 84-year-old consumer advocate and former presidential candidate issued an acerbic tweet Friday after Flake voted to advance Kavanaugh to a final vote.

Flake gave anti-Kavanaugh activists a momentary victory last week, stalling a Senate floor vote on Kavanaugh, before providing the conservative judge one of 51 votes needed to advance Friday.

"His vote for an autocratic corporatist, a criminal Iraq War advocate, a Bush/Cheney toady, a recurrent liar, and an abuser of women while under the influence of alcohol to be the next SC Justice is Kavana-ugh," Nader wrote.

[Click here for complete Kavanaugh coverage]

Nader is best-known for his role in the 2000 election, in which he took nearly 3 percent of the national vote, arguably swinging the election to Republican George W. Bush. Kavanaugh served in the Bush White House before joining the U.S. Court of Appeals for the D.C. Circuit.

Last week, Flake secured a delayed Senate vote to allow for an FBI investigation of sexual assault allegations against Kavanaugh.

On Friday, Flake joined 49 other Republicans and Sen. Joe Manchin, D-W.Va., in supporting Kavanaugh in a cloture vote. Sen. Lisa Murkowski of Alaska broke with other Republicans, voting against advancing the nomination, which is likely to win final approval this weekend.

[Also read: Senate drama: Collins mum on Kavanaugh vote. Final decision 3pm]