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More than 20 red states are filing suit after the Biden administration's recent Title IX changes that redefine sex and expand the definition of sex discrimination to include gender identity.

"Joe Biden is once again perverting the law; this time to put a radical transgender ideology ahead of the safety of women and girls," Missouri Attorney General Andrew Bailey told Fox News Digital on Thursday. 

Bailey said he takes the law "personally" as the father of a young daughter and that he's "proud" to be leading a coalition of states opposing Biden's "unconstitutional rewrite of Title IX." 

Other states filing suit against the Education Department include: Ohio, Kentucky, Virginia, Georgia, Texas, Alabama, Mississippi, Florida, Montana, Tennessee, West Virginia, Louisiana, Indiana, South Carolina and Idaho.

6 STATES SUE BIDEN ADMINISTRATION OVER NEW TITLE IX PROTECTIONS FOR TRANS ATHLETES IN GIRLS' SPORTS

President Joe Biden at podium with US flags behind him

Biden admin overhauls Title IX regulations. (Megan Varner/Getty Images/File)

Several states in the last week – Iowa, Missouri, Arkansas, Nebraska, South Dakota, North Dakota and Oklahoma – joined the legal battle and filed two additional lawsuits.

Up until Biden's revision, the 1972 law promoted gender equality and allowed sex-segregated spaces like bathrooms and locker rooms.

"The interpretation of the Biden administration is completely inconsistent with the statute and the way it’s been interpreted for decades," Arkansas Attorney General Tim Griffin said at a news conference announcing the suit alongside Bailey on Tuesday.

"We have seen this coming for a while, and we are considering what options we have to stop this rule," Griffin said, adding that it poses a threat to the First Amendment by compelling people to "speak in a particular way or risk a sort of harassment charge."

GOP SENATOR LEADS CHARGE TO RECOGNIZE ‘AMERICAN GIRLS IN SPORTS DAY’ AMID BIDEN'S TITLE IX OVERHAUL

President Biden and gender inclusive bathroom photos

Moms for Liberty and other parents groups blasted President Biden's overhaul of Title IX, arguing that it guts parents' rights and puts children in harm's way. (Getty Images/File)

Meanwhile, other red states like Florida are encouraging institutions not to comply with the new regulations. 

"Florida rejects Joe Biden’s attempt to rewrite Title IX," Gov. Ron DeSantis said in a video posted to X. "We will not comply, and we will fight back." 

Texas Gov. Greg Abbott announced in a letter to the White House last month that his state will not implement the changes either. 

"Title IX was written by Congress to support the advancement of women academically and athletically," the letter states. "The law was based on the fundamental premise that there are only two sexes – male and female. You have rewritten Title IX to force schools to treat boys as if they were girls and to accept every student’s self-declared gender identity."

Other conservative lawmakers, like Tennessee Attorney General Jonathan Skrmetti, said fellow Republican officials refusing to abide by the Biden administration’s revisions to Title IX "undermines the rule of law" and instead encouraged GOP states to fight back using the courts.

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"I don't think it's ever a good idea to skip the legal process," Skrmetti told Fox News Digital last week

The new rules revised the ways in which sexual harassment and assault claims are adjudicated on campus.

RILEY GAINES SLAMS NEW TITLE IX PROTECTIONS AS 'MOST ANTI-WOMAN' PURSUIT OF BIDEN ADMINISTRATION

Inclusive bathroom sign, inset: main image pride glad overlay with students in class

Title IX originally created sex-segregated spaces in bathrooms and locker room facilities until Biden's revisions. (Fox News Digital)

Under the revision, sex discrimination includes discrimination based on gender identity and sexual orientation. Schools are prohibited from separating people based on their biological sex, except in limited circumstances, under the provisions. Critics say the change will permit transgender people in locker rooms and bathrooms that contradict the sex appearing on their birth certificate.

LGBTQ+ students who face the new standards of "discrimination" will be entitled to a response from their school under Title IX, and those failed by their schools can seek recourse from the federal government.

Missing from the new rule, however, is a policy forbidding schools from enacting outright bans on transgender athletes competing against biological females.

Fox News' Joshua Q. Nelson contributed to this report.