As Potential Candidates Wait in the Shadows, Thompson Flirts With the Spotlight

May 5, 2007 — -- Fred Thompson may not have been onstage at Thursday night's Republican debate. But there's no question the former Tennessee senator -- and "Law and Order" actor -- is a growing presence in the presidential race.

Friday night, Thompson had the stage to himself, speaking to an enthusiastic crowd of Orange County Republicans. Introduced as a "concerned citizen who is considering a run for president," Thompson made clear he sees an opening for a different kind of candidate.

"Ever wonder why, when so many of our problems are getting larger, so many of our politicians are getting smaller?," he asked.

Despite his non-official status, polls show Thompson is already near the top of the Republican field. And strategists for real-life candidates are taking him seriously.

"Fred Thompson would be an excellent candidate," said Charlie Black, an adviser to Sen. John McCain, R-Ariz. If Thompson gets in the race, Black said, he would be in "the first tier."

More Candidates Waiting in the Wings?

It's a sign that Republican voters aren't happy with the current crop of contenders. The frontrunners -- from McCain to former New York Mayor Rudolph Giuliani to former Massachusetts Gov. Mitt Romney -- have all departed from conservative orthodoxy on various issues over the course of their careers.

And Thompson's not the only potential contender said to be eyeing a run. There's also former Speaker of the House Newt Gingrich -- who says he will make a decision by September. Rumors also continue to swirl around New York City Mayor Michael Bloomberg.

Meanwhile, on the Democratic side, former Vice President Al Gore seems to be more popular than ever, thanks to his role in an Oscar-winning documentary on global warming.

Hovering heavyweights are nothing new in presidential politics. In 1992, New York Gov. Mario Cuomo flirted with a run for months -- and famously had a plane waiting on the tarmac to take him to New Hampshire -- before ultimately taking a pass.

At the time, Cuomo said the chairman of the Democratic Party convinced him, "It would be in the best interests of the Democratic Party that I abandon any such effort now so as to avoid whatever inconvenience and disruption to the process is created by the uncertain possibility of another candidate."

In 2004, retired Gen. Wesley Clark responded to an Internet "Draft Clark" campaign by making a late -- and ultimately unsuccessful -- bid for the White House. Indeed, as Clark discovered, for candidates-in-waiting, waiting too long can be costly.

"It takes time to build a fundraising organization," said Romney adviser Vin Weber. "It takes time to build a political organization."

Still, by staying out of the race for now, shadow candidates like Thompson can get free media exposure -- without much media scrutiny.

Thompson's revelation that he had been diagnosed with non-Hodgkins lymphoma was handled in a single press release.

And while "Law and Order" reruns continue to bolster his tough-guy image, he hasn't had to answer tough questions about policy or his personal life.

Perhaps the biggest advantage non-candidate candidates have is voter fatigue. With more than eight months to go before the first primary votes are cast, voters may get tired of the current crop of contenders, creating an opening for new faces to get in late in the game.

ABC News' David Chalian contributed to this report.