Senate Conservatives Action, an arm of the Senate Conservatives Fund, launched an ad touting Sen. Thad Cochran's (R-Miss.) primary challenger Chris McDaniel as a "bold conservative champion."

It features clips of McDaniel's campaign kickoff while a narrator calls him "conservative leadership for a new generation."

It's backed by a $263,000 buy and will run for two weeks on broadcast and cable television.

Cochran has not yet decided whether he'll run for reelection in 2014, but plans to announce his intentions by the end of the month.

If he retires, he'll likely set off a scramble for his seat, which is likely to remain in Republican hands regardless.

But McDaniel has already emerged as the conservative favorite, gaining the backing of the Club for Growth, FreedomWorks, the Madison Project and the Tea Party Express.