Trump vows he'll back any candidate with a pulse against GOP senator who questioned Trump's response to protests
Donald Trump speaking at CPAC 2011 in Washington, D.C. (Gage Skidmore/Flickr)

President Donald Trump vowed he would even back a "bad" candidate as he seeks revenge against a member of his own party.

On Thursday, Sen. Lisa Murkowski (R-AK) said she agreed with former Defense Secretary James Mattis' criticism of Trump's response to the protests -- and revealed she was "struggling" over whether she will support Trump's 2020 reelection campaign.

Trump did not take kindly to the criticism.

"Few people know where they’ll be in two years from now, but I do, in the Great State of Alaska (which I love) campaigning against Senator Lisa Murkowski," Trump vowed.

"Get any candidate ready, good or bad, I don’t care, I’m endorsing. If you have a pulse, I’m with you!" he tweeted.