DeMint endorsed the former Massachusetts governor during his 2008 run for the White House, but has said since that he was unhappy with the implementation of Romney's universal healthcare law in the state.

The senator has been perhaps the most vocal advocate for the Tea Party platform in the Senate, providing him credibility with conservative voters. Coupled with his ties to South Carolina, a pivotal early primary state that has been won by the eventual nominee in every contest since 1980, DeMint's endorsement has been highly sought after. DeMint also leads a political action committee that has been influential in recruiting rising stars in the Tea Party movement, including Sens. Rand PaulRandal (Rand) Howard PaulDefense bill talks set to start amid wall fight Senate confirms two Treasury nominees over Democratic objections Liz Cheney calls for 'proportional military response' against Iran MORE (Ky.) and Marco RubioMarco Antonio RubioTrump faces difficult balancing act with reelection campaign Republicans wary of US action on Iran California poll: Biden, Sanders lead Democratic field; Harris takes fifth MORE (Fla.).