Perry has been all-in on his support of Dewhurst, despite strong opposition from within the Tea Party movement. DeMint has personally campaigned on behalf of Dewhurt’s opponent, former state Solicitor General Ted CruzRafael (Ted) Edward CruzTexas Republicans slam White House over disaster relief request Dem rep: Trump disaster aid request is 'how you let America down again' Moore endorsements disappear from campaign website MORE, who looks favored to win in Tuesday’s run-off election.

Perry previously blasted outside groups for getting involved in Texas politics, but he made it personal on Monday when he alleged DeMint is involved in the race because he wants Cruz’s vote in the Senate.

"I don’t think anybody knows David Dewhurst any better than I do. And when we talk about what’s going to be best for Texas, is a senator from South Carolina going to be better for Texas than [Sen.] John CornynJohn CornynGOP senator: ObamaCare fix could be in funding bill Senate GOP running out of options to stop Moore Texas Republicans slam White House over disaster relief request MORE?" Perry said at a phonebank event on Monday, according to local North Texas news sites Kera News and Irmo-Seven Oaks Patch.

Cornyn (R-Texas) is running to replace retiring Senate GOP Whip Jon Kyl (Ariz.) for the leadership position of Senate Republican whip. DeMint is not running, and his office strongly denied allegations made earlier this month by an influential Texas Monthly blog that DeMint’s influence in the Texas race was to gain a vote for his bid for the position.

"Sen. DeMint has not sought and does not plan to seek a Senate leadership post and reports to the contrary are simply false,” DeMint spokesman Wesley Denton said in response to Perry.

Things between Perry and DeMint were not always so testy. Before Perry dropped his bid for the Republican presidential nomination early this year, he met privately with DeMint in a likely attempt to court his influential endorsement.

Tuesday is the run-off election after a primary that was too close to call. Cruz is supported by Tea Party activists including DeMint’s Senate Conservatives Fund, the Club for Growth, former Alaska Gov. Sarah Palin and former Sen. Rick Santorum (R-Pa.) Cruz had a double-digit lead on Dewhurst in a Public Policy Polling poll released Monday.