Donald Trump announced Sunday that he’s refusing to sign any legislation until Congress passes the SAVE America Act, a voter suppression bill that would require proof of citizenship to register to vote—solving a problem that doesn’t actually exist.

“I, as President, will not sign other Bills until this is passed,” Trump wrote on Truth Social, adding his usual demands about banning trans athletes and gender-affirming care for minors—neither of which are even in the bill he’s supposedly holding out for.

Noncitizen voting is already illegal and extremely rare. But that hasn’t stopped Republicans from pushing legislation that voting rights experts say would disenfranchise millions of actual citizens who don’t have easy access to documents like passports or birth certificates.

“I would close government over it,” Trump told NBC News last week. “To me, that’s a core belief.”

The government already faces a partial shutdown over Department of Homeland Security funding. Trump’s announcement means even if Congress reaches a deal, he might refuse to sign it—holding the entire federal government hostage over a bill designed to make it harder for Americans to vote.

Senate Minority Leader Chuck Schumer wasn’t having it. “If Trump is saying he won’t sign any bills until the SAVE Act is passed, then so be it: there will be total gridlock in the Senate,” Schumer said on Twitter. “Senate Democrats will not help pass the SAVE Act under any circumstances.”

Schumer called the bill what it is: an attempt to “disenfranchise tens of millions of people.”

The bill’s backers, including Sen. Mike Lee, are pressuring Majority Leader John Thune to use a “talking filibuster” to bypass the 60-vote threshold needed to pass it. Thune acknowledged the GOP conference isn’t unified enough to pull it off and said it would be difficult to reopen the government while “in the throes of a talking filibuster.”

There’s one catch to Trump’s threat: bills automatically become law if the president doesn’t sign them within 10 days of passage. So his leverage here is mostly theatrical.

But the message is clear—Trump is willing to grind the government to a halt to pass a bill that would suppress votes, all while claiming to protect election integrity from a threat that doesn’t exist.