Washington (CNN) - One day before the Democratic challenger to Sen. Mitch McConnell of Kentucky formally kicks off her campaign, the candidate who's launched a conservative primary challenge to the top Republican in the U.S. Senate has landed an important endorsement.
The Madison Project PAC, a national conservative PAC that helps elect candidates, on Monday will endorse Matt Bevin's 2014 bid for the Senate against McConnell, who's served nearly three decades and is running for a sixth term in office next year.
The businessman from Louisville, who enjoys the support of some tea party activists and other grassroots conservatives, announced his primary challenge last week.
"The only way to change the lackluster leadership in the Republican Party is to replace the career politicians who lead the party. Matt Bevin is brave enough to storm the castle of the GOP Establishment and challenge the sitting minority leader, and we are proud to stand with him and millions of conservatives who feel disenfranchised by unprincipled GOP leaders like Mitch McConnell," said former U.S. Rep. Jim Ryun, chairman of the Madison Project, in a statement.
In a letter, the group touted Bevin's accomplishments in the private sector, saying he's "lived the American dream, coming from virtually nothing to grow businesses and create jobs." And they criticized McConnell, saying he "has become the embodiment of stale moss-covered leadership."
The endorsement could give Bevin access to a wider array of donors.
Two other conservative groups that Bevin has met with, the Senate Conservatives Fund and the Club for Growth, are also considering endorsing his primary challenge.
McConnell has wasted no time in pushing back against his new primary rival. On the day Bevin announced his bid, McConnell's team went up with a spot that attacks Bevin for taking "taxpayer bailouts" despite saying he's a "conservative businessman."
The Madison Group's endorsement of Bevin comes one day before Kentucky Secretary of State Alison Lundergan Grimes holds a campaign kickoff in Lexington, which officially begins the rollout of her Democratic challenge to McConnell.