In most presidential campaigns, after the party nominations are settled, voters experience buyer’s remorse: a sense that other candidates might have been a better choice.

What’s fascinating about the 2008 Republican race is the widespread buyer’s remorse a year before the primaries, almost a conventional wisdom that there must be a better choice for conservatives who dominate the GOP nomination process.

Largely because of that belief, a quiet effort has been under way to persuade Fred Thompson, the former movie actor, turned U.S. senator, turned television star, to run.

Thompson, who was also a Watergate prosecutor, previously discouraged suggestions he run. But he is now considering the race, amid indications his conservative record combined with a blue-collar, pickup-truck appeal to independents and moderate Democrats might make him the right guy at the right time.

If he runs, Thompson has – at least on paper – the potential to win the Republican nomination and the White House, unlike the other nonfront-runners, who for one reason or another appear unlikely to make the cut as presidential material.

He could run as a common sense Washington outsider with Ronald Reagan-class communications skills. Thompson’s name recognition is still limited, but his celebrity means his face recognition is unusually high and very favorable.

“He’d have instant credibility within the party and would be a very formidable candidate against any Democrat in November,” said former U.S. Sen. and Energy Secretary Spencer Abraham, who is neutral in the nomination fight. “He has a very solid conservative record, but like Reagan, he has been able to charm many who may not agree with him on every issue.”

Bob Beckel, who managed 1984 Democratic nominee Walter Mondale’s campaign, called Thompson potentially a Democratic electoral nightmare because of his communications skills and ability to appeal to swing voters.

If Thompson runs, look for conservatives to rally around him in an effort to save their party from Rudy Giuliani or John McCain, and the country from Hillary Clinton or Barack Obama. They like his 90-plus rating as a senator from the American Conservative Union almost as much as the zero he received from the liberal Americans for Democratic Action.

Current polls of GOP voters have former New York Mayor Giuliani ahead of Sen. McCain of Arizona, whose front-runner status has quickly evaporated. The perception that neither is right for the GOP is reflected in last week’s New York Times/CBS News poll of Republicans nationally that found 57 percent were unsatisfied with the candidates in the race.

Thompson’s backers argue there are similarities to Reagan, some superficial, others more tangible, from the days when the idea an actor running for president often was mocked.

Both entered politics late in life after other careers in the movies and television in which they were able to burnish their conservative credentials. Thompson, currently the co-star of TV’s “Law and Order,” almost always plays principled, decisive authority figures – the exact image Americans look for in a president.

Both had to be coaxed to run for office, and even admirers concede neither man has the fire in the belly to be president that generally has been required.

Thompson’s candidacy is intriguing to some because of his potential to appeal to independents and moderate Democrats, like McCain and Giuliani. But unlike them, his background and charisma could fire up the GOP base, which is searching for a champion. He’ll get to audition for them in the coming weeks when he fills in for ABC Radio’s Paul Harvey, whose show is a staple for conservatives.

Perhaps the largest stumbling block to a Thompson candidacy might be his close friendship with McCain, whose candidacy he backed strongly in 2000 against George W. Bush in the GOP primaries.

In the year before an election, presidential politics resembles Wall Street’s options market in which investors gauge a stock’s future worth. There may be a lot of Republicans thinking about buying options on Fred Thompson.