Giuliani Worried by Fred Thompson

Former Tennessee Sen. Fred Thompson officially joins the presidential race on Thursday, and Rudy Giuliani and his team are watching closely to determine how much of an impact his candidacy will have on Giuliani.

"He's a Southerner, and he's a senator, and that gives him credibility," Barry Wynn, a top Giuliani adviser in South Carolina, tells Newsday. "He's certainly weaker today in terms of the level of enthusiasm of his supporters than he was a month ago ... but I certainly see him as serious competition."

Giuliani currently sits atop every major national poll, and is leading decisively in states like California and Florida. But he still faces deep skepticism from conservatives who drive the nominating process. Those are the same people who are likely to be Thompson supporters, analysts say, and that could mean Thompson won't fade any time soon.

"I was totally dismissive of his chance to get the nomination, and I'm not dismissive anymore," Stu Rothenberg, a Washington political analyst, told Newsday. "He's hung in there."

The worry for Giuliani is that Thompson could prove just as appealing to conservatives on tax cuts and terrorism -- with the added bonus of agreeing with them on social issues like abortion and gun control. It's a theme Thompson's advisers already have suggested they will play up, the importance of nominating a candidate who embodies every part of the party's beliefs.