NAPLES, FLA. ? Republican Fred Thompson, the actor-politician who attracted more attention as a potential presidential candidate than as a real one, quit the race for the White House on Tuesday after a string of poor finishes in early primary and caucus states.

“Today, I have withdrawn my candidacy for president of the United States. I hope that my country and my party have benefited from our having made this effort,” the former Tennessee senator said in a brief statement.

Thompson’s fate was sealed last Saturday in the South Carolina primary, when he finished third in a state that he had said he needed to win.

In the statement, Thompson did not say whether he would endorse any of his former rivals. He was one of a handful of members of Congress who supported Arizona Sen. John McCain in 2000 in his unsuccessful race against George W. Bush for the party nomination.

Thompson, best known as the gruff district attorney on NBC’s “Law & Order,” placed third in Iowa and South Carolina, two states seemingly in line with his right-leaning pitch and laid-back style, and fared even worse in the four other states that have held contests thus far. Money already tight, he ran out of it altogether as the losses piled up.

Thompson, 65, exits the most wide open Republican race in half a century; three candidates have won in the six states that have voted.

In Florida, McCain, former Massachusetts Gov. Mitt Romney and former New York Mayor Rudy Giuliani are battling for the lead ahead of its Jan. 29 primary, while former Arkansas Gov. Mike Huckabee evaluates his next steps amid money troubles.

Thompson’s withdrawal capped a turbulent 10 months that saw him go from hot to not in short order.

He began toying with a presidential run last March, emboldened by a fluid Republican nomination fight and a restive conservative GOP base. He also was charmed by resounding calls for him to get into the race – and his meteoric springtime rise to the top of national and state polls.

Fans trying to draft him as a candidate launched an online effort, seizing on his conservative Senate voting record as well as his lumbering 6-foot-5 frame and deep baritone as they argued that he was right out of central casting. They painted him as the second coming of Ronald Reagan and the would-be savior of a Republican Party demoralized after electoral losses in 2006 at all levels of government.

Expectations rose higher – and his standing in polls started to fall as he failed to meet them.

Thompson formally an-nounced his bid in early September, but hit a rocky patch from the get-go. He skipped a Republican debate in New Hampshire, annoying some in the state, to announce his candidacy on NBC’s “Tonight Show” with Jay Leno.

His easygoing style and reputation for laziness translated into a light campaign schedule that raised questions about his desire to be president. A spate of inartful answers to campaign-trail questions – on everything from the Terri Schiavo case to Osama bin Laden – didn’t help matters.

Though his star had faded, Thompson earned positive reviews for a series of debate performances last fall and earned an endorsement by the National Right to Life Committee.

Thompson first made a name in Washington politics three decades ago when he served as minority counsel to the Senate Watergate Committee. Thompson, who was 30 at the time, was appointed to the high-profile job by his political mentor, then-Sen. Howard Baker of Tennessee, who was the top Republican on the committee. Thompson had managed Baker’s re-election campaign and had been an assistant U.S. attorney in Nashville.