Republican Presidential candidate Ron Paul tonight received the endorsement of South Carolina state Sen. Tom Davis, a state lawmaker popular with tea party activists.

Speaking at a rally in Myrtle Beach, Davis praised Paul's "drastic and radical" efforts to reign in government spending.

"There is only one candidate that is talking about this problem to the degree, at the scale, and with the scope that it needs to be talked about," Davis said. "You can't nibble around the edges anymore."

Davis blamed lobbyists and loopholes for "rotting out our republic to the core."

"That's what's happening in South Carolina and that's what's happening to our nation," he said.

The Paul campaign describes the announcement as "consequential" and "game-changing," adding in a statement that it "virtually assures" that Paul will get the support of fiscal conservatives in the "First in the South" primary.

Davis wrote on his Facebook page that he would back "the one candidate in the race for president who has consistently stood for taxpayers."

Davis served as chief of staff to former Gov. Mark Sanford, who disappeared for several days in June 2009 and later resigned after admitting to an affair with another woman.

Paul returns to the campaign trail in South Carolina after taking a three-day break from campaigning to spend time with his family.

The congressman predicted earlier in the week that he will finish in the "top tier" in the state's primary Jan 21.