Michael Steele was the official head of the Republican Party until late last year, and businessman Herman Cain briefly led in the polls for the 2012 GOP presidential nomination.

But the black Republican whose endorsement the remaining GOP presidential candidates truly want belongs to a man who is much less well-known: Tim Scott. The freshman House member from Charleston has credibility with both the GOP’s Tea Party and establishment wings, and a candidate who gets his backing before Saturday’s critical South Carolina primary could get at least a temporary boost in momentum.

Scott seems aware he is having his moment on the national stage and is carefully weighing his options. He has not said if he will back any of the Republicans before Saturday, even as he told CNN this weekend all of the campaigns have courted him.

“This is a very difficult choice because each candidate really represents something that I really like, I believe the country needs,” he said on NBC’s Meet the Press in an interview on Sunday. “But the question that Senator Graham was talking about is the equation of who matches my values, who can win, and that’s the guy we’ll support.”

Scott’s indecision is not surprising; the state’s senators, Lindsey Graham and Jim Demint, have also not announced endorsements. And it’s not clear any endorsement could stop former Massachusetts governor Mitt Romney, who has won the first two primaries and is favored in South Carolina because voters who don’t like Romney are likely to split their votes between former House Speaker Newt Gingrich, former Pennsylvania Senator Rick Santorum and Texas Gov. Rick Perry.

But a Scott endorsement, particularly of Santorum, could alter the race. A group of national evangelical leaders are now supporting Santorum and the backing of Scott, who is closely tied with South Carolina Tea Party activists, could help consolidate the anti-Romney vote behind the former senator.

It’s not clear if Scott is ready to make such a risky endorsement, which could hurt his rapid political rise. The former Charleston city councilman was elected in 2010 in a heavily-Republican district that comprises parts of both Charleston and Myrtle Beach, winning in a GOP primary that included the son of longtime South Carolina senator Strom Thurmond.

Scott was strongly backed by Tea Party-affiliated groups in South Carolina and around the country, and anti-establishment Republicans like Sarah Palin.

Republican leaders quickly tapped him to serve in the party’s leadership in Congress, as Scott presents a rare combination: an African-American in a party with few black members, a favorite of the Tea Party and a man elected in the GOP wave of 2010.

On Capitol Hill, Scott has been an ardent opponent of President Obama’s, co-authoring legislation to defund Obama’s universal health care law. At the same time, Scott has not always hewed to the agenda of House GOP leaders, opposing a deficit reduction plan from House Speaker John A. Boehner over the summer because he felt it did not go far enough to reduce spending.

Scott has gained influence in the GOP by not being perceived as a controversial or camera-hungry figure like Steele or Cain. He could use that clout now, but Scott has hinted that he expects Romney to win South Carolina and the GOP nomination, and that he would not be upset by that outcome.

“I don’t care much if it’s Gingrich, Santorum, Romney,” he said at a Tea Party event in Myrtle Beach on Monday, adding, “as long as it’s someone in the White House who’s not in the White House right now.”

Follow Perry Bacon Jr. on Twitter at @perrybaconjr