Senate Majority Leader Mitch McConnell is scheming to slam the door of the Senate in the face of another conservative Republican like Sen. Ted Cruz.

McConnell’s super PAC has aggressively bought air time to ensure establishment candidate Rep. Todd Young replaces retiring Sen. Dan Coats. Young is running in the primary against Rep. Marlin Stutzman – a member of the House Freedom Caucus who voted against former Speaker John Boehner. In addition to McConnell’s super PAC, establishment GOP ally the U.S. Chamber of Commerce has spent $1 million to promote Young and keep out anti-establishment Stutzman.

“We must commit ourselves to avoiding the constant cycle of brinkmanship by working across party lines to address issues like job creation, stagnant personal incomes, our unsustainable national debt and rising health-care costs,” Young said in 2013 when he voted to end the government shutdown.

In addition, Young has regularly voted against the conservative alternative to House Republicans’ annual budget proposal.

CNN reports that McConnell views Stutzman as “a potential troublemaker in the Senate GOP Conference, much like Cruz.”

The report continues:

The move marks a new front in the simmering wars between the establishment and the right flank of the party, a battle that has dominated the GOP since the 2010 midterms and is roiling the 2016 presidential contest…

In an interview with CNN, Stutzman pointedly accused McConnell of retaliating against him for his vote against Boehner last year, saying it “would be a lot harder” for him now to back the Kentucky Republican as Senate leader if he wins in November. He had previously signaled he’d back McConnell as leader.

“They don’t want me to be the next senator from Indiana,” Stutzman said.

“Todd Young is going to vote ‘yes’ for Mitch McConnell, and Mitch McConnell knows that I voted against John Boehner,” he added. “Todd Young is a yes-man.”

Stutzman has allied himself with the Club for Growth and the Senate Conservatives Fund, and now the Indiana Senate primary has become key for the GOP and its ability to hold onto its narrow majority.

Former Indiana Rep. David McIntosh, head of the Club for Growth, said Young “is the establishment choice.”

“Marlin is the outsider running in the race,” he added.

Grassroots parents who have been fighting against Common Core in Indiana have endorsed Stutzman.

Conservative activist Erin Tuttle writes:

Hoosiers still deciding between Marlin Stutzman and Todd Young will find a stark difference between their votes on important education legislation. Marlin Stutzman has a consistent record of standing with Hoosier parents and students and supporting policies that reduce federal control over education. Todd Young has chosen to stand with Republican leadership to help cement the education reforms of the Obama Administration into federal law.

Indystar reports:

In a year in which anti-establishment candidates are collecting the most GOP presidential delegates, Young is the Senate Republican candidate who best represents party leaders. He is backed by the U.S. Chamber of Commerce, which is running $1 million in ads touting Young’s candidacy. He has a long list of endorsements from Indiana GOP officials and is supported by outside groups with ties to Senate Majority Leader Mitch McConnell, R-Ky.

“The D.C. establishment thinks that they can buy your vote,” said Stutzman. “They have chosen Todd Young to play as their puppet in this upcoming election.”