In a unique format, ABC will host two debates tonight starting at 7:00 PM EDT with the Republicans taking the stage at St. Anselm College first followed immediately by the Democrats 90 minutes later:

The network set rules to narrow the field. Candidates had to meet at least one of three criteria: 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.

Democrats Joe Biden and Chris Dodd took some of the pressure off ABC by quitting the race Thursday night.

"In previous debates where the stage was more crowded you had to make sure all of the candidates got fair time," said David Chalian, ABC News political director. "Here you will have more time to go in depth on the issues." ABC said it believed its rules were inclusive, while also ensuring viewers get a thorough look at the probable next president.

"We're regretful that we're not going to be in it," said Roy Tyler, a spokesman for Hunter. "We're just going to keep working. I think it's a mistake on their part to exclude any viable candidate at this point."

Democratic presidential candidate Dennis Kucinich filed a complaint with the FCC on Friday after ABC News excluded him, fellow Democrat Mike Gravel and Republican Duncan Hunter from its prime-time debates on Saturday. Kucinich argued that ABC is violating equal-time provisions by keeping him out of the debate and noted that ABC's parent Walt Disney Co. had contributed to campaigns involving the four Democrats who were invited.

"ABC should not be the first primary," the Ohio congressman said in papers filed at the Federal Communications Commission.

“The first-in-the-nation New Hampshire primary serves a national purpose by giving all candidates an equal opportunity on a level playing field," said Republican chair Fergus Cullen. "Only in New Hampshire do lesser known, lesser funded underdogs have a fighting chance to establish themselves as national figures."