The roster of participants for ABC's back-to-back, prime-time Republican and Democratic debates Saturday in New Hampshire will be determined after results of Thursday's Iowa caucus become clear.
Fox, meanwhile, has invited five GOP candidates to a forum with Chris Wallace scheduled for its mobile studio in New Hampshire on Sunday., , , and received invites, leaving Paul and Duncan Hunter on the sidelines.
The network said it had limited space in its studio - a souped-up bus - and that it invited candidates who had received double-digit support in recent polls.
In a nationwide poll conducted Dec. 14-20 by The Associated Press and Yahoo, Thompson had the support of 11 percent of GOP voters and Paul was at 3 percent.
Paul was tied with Thompson for fifth in New Hampshire in the most recent Los Angeles Times/Bloomberg poll, each with the support of 4 percent of likely voters. Among all New Hampshire voters, Paul led Thompson 6 percent to 4 percent, but that was within the poll's margin of error.
Jesse Benton, Paul's spokesman, said it was a "big mistake" not to include his candidate, especially given Paul's recent success in fundraising. He said the campaign has been trying to reach Fox News to explain the decision, but its calls had not been returned.
"There very well might be some bias," Benton said. "Ron brings up some topics that aren't very popular with Fox News, as in fiscal responsibility and withdrawing from the war in Iraq ... that does leave us scratching our heads a little bit about whether it was deliberate. Based on metrics, I don't see how you can possibly exclude Dr. Paul."
Some livid Paul supporters are distributing e-mails calling for a boycott of Fox advertisers.
A Fox representative did not immediately return calls for comment about the complaints.
Paul has been invited to a GOP forum that Fox News is sponsoring in Myrtle Beach, S.C., on Jan. 10, Benton said.
To participate in ABC's Saturday night debate, Republican and Democratic candidates must meet at least one of three benchmarks: place first through fourth in Iowa, poll 5 percent or higher in one of the last four major New Hampshire surveys, or poll 5 percent or higher in one of the last four major national surveys.
ABC News anchor Charles Gibson said the criteria were actually quite inclusive. He defended the network taking the initiative in effectively narrowing the field at a point when no actual voters had cast a ballot, except for Iowa caucusgoers.
"You will have had a year's politicking," he said. "You will have had, I think by count, about 641 debates. You will have had national polls and state polls and one state's vote. I think that's pretty indicative."
Gibson said ABC explained the rules for participation in a conference call with all the campaigns and "nobody said, 'How dare you!'"
Gibson is moderating both debates, each 90 minutes long, with a brief intermission between the two.