What Will Tom Do?

Republican presidential candidate Tom Tancredo will make "a major announcement regarding the campaign" tomorrow afternoon in Iowa, a tantalizing tease that has sparked speculation about whether his candidacy may be coming to an end.

Tancredo has remained in single-digits in Iowa polls despite spending most of his time there over the last year. He has been focused almost exclusively on his opposition to illegal immigration, the top issue for likely GOP caucus-goers. In a recent Republican debate, Tancredo signaled that he was happy with the positions being espoused by his primary opponents on the issue. "For a guy who usually stands on the bookend here, aside, and just listens all the time, that's kind of frustrating, you know, in other debates. I have to tell you, so far, it's been wonderful," he said. "Because all I've heard is people trying to out-Tancredo Tancredo."

CBS News Chief Political Consultant Marc Ambinder reports that the "scuttle" is Tancredo will exit but no word yet on who he may endorse, if anyone. One source with ties to the campaign told Tancredo is playing it close to the vest, but speculated that Fred Thompson would be a logical choice for Tancredo to back.

The Tancredo campaign did not respond to calls and e-mails inquiring about the announcement.