Fox News contributor Lisa Boothe said that Rep. Nancy Pelosi's biggest challenge in her bid to once again become House Speaker will lie on the House floor.

Boothe said that a growing progressive wing of the Democratic Party could be a potential roadblock for Pelosi (D-Calif.), who served as Speaker from 2007 to 2011.

"That's gonna be a really big challenge that she's facing," Boothe said.

At least 17 House Democrats, including incumbents and incoming members, have signed on to a document saying they will not support Pelosi.

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"If it's this hard for her to wrangle her caucus, I think it's sort of a sign of what's to come for her," Boothe said.

Although she believes Pelosi will ultimately regain the Speaker's gavel, Boothe said the California Democrat might see some defectors.

Rep. Marcia Fudge (D-Ohio) said last week that she's contemplating running for speaker.

When asked about a potential challenge from Fudge during a Capitol Hill press conference, Pelosi replied, “Come on in, the water’s warm.”

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