The GOP primary challenger to Senate Minority Leader Mitch McConnell (R-Ky.) received an endorsement Friday from the Senate Conservatives Fund, a PAC founded by former Sen. Jim DeMint (R-S.C.).
The endorsement of Kentucky businessman Matt Bevin escalates the effort by outside conservative groups to back primary challenges next year against those congressional lawmakers who finally voted for the bipartisan budget deal. On Thursday, the Senate Conservatives Fund, the Club for Growth and the Madison Project all endorsed Mississippi state Sen. Chris McDaniel, a primary challenger to Sen. Thad Cochran (R-Miss.). The Madison Project had already endorsed Bevin.
McConnell himself helped craft the budget deal that left Obamacare virtually unscathed. The Senate Conservatives Fund also hammered him over a provision in the legislation boosting funding for the Olmsted Locks and Dam in Kentucky from $775 million to $2.9 billion.
"Matt Bevin is a true conservative who will fight to stop the massive spending, bailouts, and debt that are destroying our country," said Senate Conservatives Fund Director Matt Hoskins in a statement. "He is not afraid to stand up to the establishment and he will do what it takes to stop Obamacare. We know that winning this primary won't be easy. Mitch McConnell has the support of the entire Washington establishment and he will do anything to hold on to power. But if people in Kentucky and all across the country rise up and demand something better, we're confident Matt Bevin can win this race."
The Senate Conservatives Fund had previously targeted open seats that had been held by Democrats. But since DeMint left the Senate to run the Heritage Foundation at the beginning of 2013, the fund also has set its sights on incumbent Republican senators.
McConnell's campaign dismissed the endorsement.
"Matt Bevin now has the dubious honor of standing with a self-serving D.C. fundraising group that made its name by recruiting and promoting unelectable candidates that ensured Barack Obama a majority in the Senate," said McConnell spokeswoman Allison Moore. "They clearly care less about Kentuckians than they do about their reputation for supporting laughably bad candidates."
This story has been updated with comment from McConnell's campaign.
ALSO ON HUFFPOST:
How will Trump’s administration impact you? Learn more