Sen. Lindsey GrahamLindsey Olin GrahamDHS chief takes heat over Trump furor Overnight Defense: GOP chair blames Dems for defense budget holdup | FDA, Pentagon to speed approval of battlefield drugs | Mattis calls North Korea situation 'sobering' Bipartisan group to introduce DACA bill in House MORE (R-S.C.) is touting his conservative bona fides on economic issues in a new ad campaign.

"He's been a 'hero of the taxpayer,' the 'taxpayers' friend' and a 'guardian of small business.' He was ranked as a top five Senate budget-cutter by National Taxpayers Union Foundation," a narrator says in his new TV ad. "He opposed ObamaCare from day one, voted to repeal it and introduced legilation giving states the option to opt out. Sen. Lindsey Graham: A conservative leader who gets things done."

Graham has taken heat from the right for backing immigration reform, the Troubled Asset Relief Program, and some of President Obama's appointees, and is facing a number of Tea Party primary challengers.

But he looks to have the big advantage in the race — polls show him closing in on the 50 percent he needs to avoid a runoff in the June primary, and the $7.6 million he had in the bank as of the beginning of the year dwarfs what his opponents have hauled in.

He's using that cash advantage to boost himself early in this race — this is his second six-figure statewide ad buy. Graham's campaign is also running a radio ad touting his opposition to ObamaCare.