Fox said it would use the five most recent national polls to determine which candidates would compete in the main debate, and the channel ultimately calculated that Ohio Gov. John Kasich (R) would make it into the debate, pushing Texas Gov. Rick Perry (R) into the second-tier debate.
Yet Maddow pointed out that Fox did not use the fifth most recent national poll -- an NBC/WSJ poll conducted through July 30. The channel instead used a Quinnipiac University poll conducted through July 28.
Though using either the NBC/WSJ poll or the Quinnipiac poll would have scored Kasich a place at the top-tier debate, the Quinnipiac poll, which had Kasich leading Perry by 3 points, gave the Ohio governor a more definitive lead.
"They violated their own previously-announced criteria of what polls they’d use. They moved the goalposts in the middle of the game in a way that makes it look like they were trying to justify the lineup of who they wanted on stage," Maddow said Tuesday night.
Fox News announced Tuesday night that the channel disregarded the NBC/WSJ poll "because it did not meet our criterion that the poll read the names of each Republican candidate in the vote question," according to Politico.
Despite Fox News' reasoning, Maddow said that their choice in polls made it look as though they disregarded the NBC/WSJ poll to give Kasich a larger lead.
"There is something qualitatively different between this just looking stupid and the system looking rigged — rigged by a cable news channel in order to justify apparently what they want," she said.
Watch Maddow's segment on MSNBC: