The Nation - Candidate who is not there upstages Republican debate - Fred Thompson announces his bid on a talk show couch, prompting needling from his opponents.

"Maybe we're up past his bedtime," Sen. John McCain of Arizona quipped of the absentee candidate during the New Hampshire debate.

Former Arkansas Gov. Mike Huckabee took a folksy dig, comparing Thompson to country singer George Jones, "who was often called 'no-show George' for not showing up at his concerts."

"Maybe," Huckabee said, "Sen. Thompson will be known as the no-show for the presidential debates."

The subject of the mostly good-natured needling ended months of deliberations with a simple statement, delivered just about an hour earlier at a taping of "The Tonight Show With Jay Leno."

"I'm running for president of the United States," Thompson said, to loud cheers.

The former Tennessee senator, an actor known to millions as a district attorney on NBC's "Law & Order," set out quickly to capture the support of conservatives who have been wary of the party's top White House contenders.

Thompson avoided mentioning leading opponents Rudolph W. Giuliani of New York and Mitt Romney of Massachusetts by name, but took gentle swipes at them nonetheless for the liberal and moderate stands they once took in their home states.

"In 1994, when I first ran, I advocated the same common-sense conservative positions that I hold today," Thompson said in a video posted on his website less than two hours after the debate ended.

For months, polls have found Republicans less pleased than Democrats with their candidate lineup. Social conservatives have been especially uneasy with the candidates' mixed records on abortion, guns and immigration.

"The opening is there to be the consensus conservative," said Republican pollster Tony Fabrizio, who is not advising a candidate in the primaries. "The question, is can [Thompson] step into that -- can he make that a reality?"

Thompson faces other questions. In the 1990s, he was a paid lobbyist for a family-planning group that was seeking to ease restrictions on abortion counseling. He also has written on candidate questionnaires that abortion should be legal in the first three months of pregnancy and, in general, should not be criminalized, though as a senator from 1994 to 2003, he voted along antiabortion lines.