Sanchez, in her fifth term representing California's 47th District, reportedly is furious at fellow California Democrat, Baca, for alleged derogatory remarks. In an interview with Politico.com she accused him of calling her a "whore."
In a statement received by FOXNews.com Wednesday night, Sanchez said, "Last year, I and other members of the caucus voiced our strong opposition to Mr. Baca's chairmanship due to a violation of election rules. An official response to our inquiry is still in question."
"It's unfortunate that Congresswoman Loretta Sanchez has decided to resign from the Congressional Hispanic Caucus and has chosen to air baseless statements," Baca said in a written statement. "We cannot allow distractions or personality conflicts to interfere with the important work we are doing."
Sanchez's protest of Baca's chairmanship of the caucus — which represents 21 Hispanic House Democrats — dates back to November 2006, when she voted against him for the leadership post. Four other women members, including Sanchez's sister, Rep. Linda Sanchez, abstained.
Just a few weeks ago, four female lawmakers requested that Baca repeat the election because the group did not follow it's own rules of using secret ballots. Sanchez's spokesman said they never received a response.
Sanchez told Politico.com that "I'm not going to be a part of the CHC as long as Mr. Baca illegally holds the chair … I told them no. There's a big rift here."
Baca, representing California's 43rd District since 1999, responded to Politico.com that Sanchez's comments are "categorically untrue."
This is not the first split in the CHC. Last March, six caucus members — including the Sanchez sisters — cut ties to the group's campaign arm after it helped finance the unsuccessful campaigns of Baca's two sons for seats in the California Legislature.
Baca defended the decision to give money to them and other nonfederal candidates, saying the caucus should seek to build a farm team. Opponents said the focus instead should be on electing Latino House members.
Sanchez said she will continue to advocate for the Hispanic community and serve as the chairwoman of the Banking and Finance Committee for the Congressional Hispanic Caucus Institute, a non-profit organization.