Elon Musk made good Tuesday on an earlier vow to sue the California Coastal Commission — and the billionaire CEO's company has to prove bias to win the case.

In the lawsuit, filed in the US District Court for the Central District of California, Musk's SpaceX accuses the commission of "unconstitutional overreach" after members criticized his political leanings during a meeting about whether to approve more frequent SpaceX launches off the California coastline.

"Rarely has a government agency made so clear that it was exceeding its authorized mandate to punish a company for the political views and statements of its largest shareholder and CEO," the lawsuit says.

The company accuses the commission of unfairly asserting regulatory powers because it disagreed with Musk's politics.

The California Coastal Commission, which regulates the use of land and water in the state's coastal zone, "has engaged in naked political discrimination" against SpaceX, the lawsuit alleges.

SpaceX says the commission's decision is in violation of the First and 14th amendments.

"Thankfully, the fundamental rights of free speech and due process enshrined in our Constitution prohibit precisely this kind of political witch hunting and abuse of power by rogue state agency officials," the lawsuit says.

The space rocket company also argues in the lawsuit that the commission was trying to "unlawfully regulate space launch programs" at the Vandenberg Space Force Base in Santa Barbara County.

Last week, the commission denied a request by the US Space Force to increase the number of annual Falcon 9 rocket launches from 36 to 50 at the Vandenberg military base.

In a 6-4 vote, the commission said SpaceX, as a private company, was not exempt from obtaining a permit, even though it works closely with the government.

While Musk's politics weren't referenced in the decision, they were discussed during a public meeting by commission members. Commissioner Gretchen Newsom said Musk was "spewing and tweeting political falsehoods" and accused him of prioritizing profits over employee well-being.

The commission's chair, Caryl Hart, added that Musk had "aggressively injected himself into the presidential race."

"The Commission's public hearing record indisputably shows overt, and shocking, political bias," SpaceX's lawsuit says. "There is no pretext — the political basis of the Commission's action is plain for all to see."

The lawsuit adds: "To make it even clearer that the Commission's decision was based on its political biases and other irrelevant, misplaced concerns, the Commission recently approved another commercial space launch operator launching up to 60 launches a year from the same Base, accepting that this operator's launch program, including commercial launches, are federal agency activities."

The commission declined to comment on the lawsuit. A spokesperson initially told Business Insider on Wednesday the lawsuit's claim that the commission approved another operator for up to 60 launches was false but later said he misspoke.

Jim Cantrell, the CEO of Phantom Space, told BI that his company was the other operator mentioned in SpaceX's lawsuit against the commission.

In a post on X before the lawsuit was filed, Musk called the commissioners' comments "incredibly inappropriate" and vowed to retaliate in court.

"I have done more to advance sustainable energy & help the environment than maybe anyone ever," Musk wrote Tuesday in a post, "which is not exactly a 'far-right' position."

He added that the commission "should resign immediately."

SpaceX did not immediately respond to a request for comment.

Legal experts told BI a day before the lawsuit was filed that Musk's complaint could be successful — if Musk could prove bias.

Eugene Volokh, a First Amendment scholar, said victory for Musk would depend on what evidence Musk has that his political speech played a role in the commission's decision.

"Denying a license — or other government retaliation — based on an applicant's political speech, or the political speech of the applicant's owner or manager, generally violates the First Amendment," said Volokh, a professor of law at the University of California, Los Angeles, and senior fellow at the Hoover Institution at Stanford University. "Indeed, that's even true of denial of a contract where government money is being used."

David Driesen, a law professor at Syracuse University, said: "Politicians have a First Amendment right to criticize Musk, so accusing him of spreading falsehoods is protected political speech."

"On the other hand," Driesen said, "if Musk could show that the decision to deny his application was punishment for his falsehoods, that might make out a First Amendment violation."

Driesen added that "any good court would reject the idea that the commission punished him for his speech, since the decision was based on other grounds. "

The law professor said that, ultimately, a judge might "admonish" the California Coastal Commission and point out that commissioners couldn't punish applicants for their speech through their decisions.

Volokh said if the commission's decision was based on other grounds "and would have been reached on those grounds even setting aside" Musk's politics, then "there's no First Amendment violation."

"But if a court concludes that it's more likely than not that the result would have been different but for Musk's speech, then there would be a violation," Volokh added.

Sarah Kreps, a political scientist and the director of the Tech Policy Institute at Cornell University, said that the commissioners' comments, even if "politically motivated," did not directly constitute a legal violation of Musk's free-speech rights.

"It is possible that the lawsuit could be dismissed as lacking grounds for a constitutional claim," Kreps said.

Kreps added that political discourse being integrated into regulatory matters had become "increasingly common in highly publicized cases involving influential figures like Musk."

"It can raise questions about the impartiality of such bodies, even if the legal framework is followed," she said.

Musk's company filed the suit days after a massive win for SpaceX when it conducted a successful test flight Sunday of its Starship and Super Heavy booster — a massive rocket that Musk hopes will, one day, transport humans to Mars.

This story was updated.