By John McArdle, CQ-Roll Call

Democratic Rep. John M. Spratt Jr. is in his 14th term representing South Carolina’s 5th District and usually has little trouble winning re-election. But it appears that national Republicans are set on giving the Budget Committee chairman more than simply a token challenge this cycle.

This week, the National Republican Congressional Committee is airing ads attacking Spratt for his vote on the House version of the controversial health care bill.

The NRCC’s willingness to spend money to soften up Spratt combined with the recent entry of a serious GOP challenger in the contest has prompted CQ Politics to change the rating of the race from Safe Democratic to the more competitive classification of Likely Democratic.

Republican freshman state Sen. Mick Mulvaney announced his intention to challenge Spratt in early November. Mulvaney is a former one-term state House representative who is viewed as an up-and-comer in the state party.

In his early days on the campaign trail, Mulvaney has tried to make the case that after nearly three decades in Washington, D.C., Spratt has become out of touch with his conservative district, which Sen. John McCain , R-Ariz., won by 7 points in the 2008 presidential race.

Mulvaney called the health care bill “the biggest expansion of government in history,” in a statement released after the House passed its version of the legislation on Nov. 7.

“It represents the biggest spending increase in history. It represents the biggest intrusion of government into our lives in history,” he said. “There may have been a time when John Spratt would not have allowed this to happen without a fight. Those days are apparently gone.”

Still, it remains to be seen whether Mulvaney will gain any traction.

Spratt, the chairman of the House Budget Committee, cruised to re-election in 2008 with 61.5 percent of the vote over Republican Albert Spencer, who posted 37 percent. He faced his toughest opponent in 2006, wealthy state legislator Ralph Norman, and won with 56.9 percent of the vote to Norman’s 43.1 percent.

According to his latest Federal Election Commission report, Spratt had a little less than $600,000 in cash on hand as of Sept. 30.

To see how all the 2010 House races are shaping up, check out CQ Politics election map.