Senate Minority Leader Mitch McConnell of Kentucky now has another reason to back Trey Grayson in the GOP primary race for Kentucky's open Senate seat.

From the AP:

LEXINGTON, Ky. — Front-runner Rand Paul said in a U.S. Senate debate Monday night that he may not support Kentucky's other senator, Mitch McConnell, for minority floor leader if he's elected.

"I'd have to know who the opponent is and make a decision at that time," Paul said in a sometimes testy televised debate, the final face off in what has become an increasing acrimonious race to replace Sen. Jim Bunning.

His chief Republican opponent, Kentucky Secretary of State Trey Grayson, said he "proudly" would vote for McConnell. McConnell endorsed Grayson in the May 18 primary. South Carolina Sen. Jim DeMint, who endorsed Paul, has been mentioned as a potential McConnell opponent for minority leader, though DeMint has said he has no such intention.

Kentucky is one of three states holding big primaries a week from today. Democrats in Pennsylvania and Arkansas will decide whether they want their incumbent senator, Arlen Specter and Blanche Lincoln, to represent them on the general election ballot in November.

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