A Maine state legislator posted about trans athletes in women’s sports on her Facebook page — then got banned from speaking or voting on the State House floor.

Now she’s suing the House speaker for violating her First Amendment rights.

“It was a bad move politically for the Democrat majority to censure me for speaking up for Maine girls and their right to a fair, safe, and level playing field, especially because 80% of Americans feel as I do,” Rep. Laurel Libby (R-Minot) told The Post.

It all started on February 17 when Libby, a Republican from Maine’s 64th District,  posted a photo of a Maine high school transgender pole vaulter standing on the first-place step of a state championship podium.

“We’ve learned that just *ONE* year ago John was competing in boy’s pole vault… that’s when he had his 5th place finish,” Libby wrote on her Facebook page. ”Tonight, ‘Katie’ won 1st place in the girls’ Maine State Class B Championship.”

The athlete’s first-place win shot their school’s team to a championship win by a single point.

“I comment about a wide variety of current issues here in Maine, so I did not expect a big issue about it,” Libby said of the post.

“It was a public photo from a public event that an individual chose freely to participate in and step up on a podium during.”

The Democratic House speaker and majority leader in Maine quickly caught wind of the post and demanded she take it down. When she refused, they introduced a motion to censure her, citing the fact that the photographed individual is a minor.

The resolution, which bars her from speaking on the House floor or voting on legislation until she apologizes, passed along partisan lines in a 75-70 vote.

“We’re getting into really dangerous territory, because speech is not free when a simple majority can silence a member of the minority party,” Libby said.

Her lawsuit alleges the Democratic majority violated Libby’s constitutional rights because the Facebook post is protected by the First Amendment. Free-speech attorney Greg Lukianoff, president of the Foundation for Individual Rights and Expression, agrees.

“Stripping an elected representative of her right to speak and vote for refusing to delete a lawful Facebook post is a blatant violation of free speech and the First Amendment,” Lukianoff told The Post.

“The Constitution doesn’t grant lawmakers the power to muzzle colleagues for making arguments on one of the hottest topics of the day in a way that they don’t like.”

The debacle helped ignite a contentious exchange between Maine Gov. Janet Mills and President Trump over transgender athletes in the White House last week. 

The administration has cut funding to Maine public universities, as the state continues to defy Trump’s executive order to keep trans athletes out of women’s sports, accusing the state of failure to comply with Title IX.

 Meanwhile, Libby says her censure harms the voters who elected her to represent them.

“It’s a silencing of my constituents, and it says your vote doesn’t matter, your voice doesn’t matter, and we don’t think that you deserve representation in the State House,” she said.

She also thinks “100%” the move will cause her colleagues to self-censor for fear of the same retribution.

“If it’s so easy to silence someone who you disagree with on policy, that absolutely shuts down policy debate, because there’s a danger that you can lose your voice and your vote simply by expressing a different opinion,” the lawmaker said.

In a further shock, on Wednesday, all of Maine’s federal judges recused themselves from the case, sending it to the District of Rhode Island. Libby declined to comment about that development.

The defendants have 21 days to respond to Libby’s suit.

As she awaits their response, she worries what Maine girls will make of the Democrats’ move to silence her.

“It’s a terrible message to send to our young women,” she said. “Our female athletes are already having to compete against biological males, and now they’re being told by this censuring action not to even speak up about it — to sit down and shut up, essentially.”