Senate Republicans’ Don Blankenship nightmare will last a least a little longer. The disgraced coal baron says he plans to file the paperwork on Tuesday for a third-party campaign for U.S. Senate in West Virginia, after failing to win the GOP nomination in May.

Given the state’s so-called sore loser law, Blankenship’s Constitution Party candidacy remains only theoretical for now. State officials are expected to refuse to certify his paperwork, but he is promising to use “all legal means necessary” to get his name on the ballot. If he prevails, it would be a major boost to Democratic Sen. Joe Manchin and a major blow to Republicans, who had to pull out all the stops to prevent Blankenship from becoming their nominee.

At issue is the state law that bars a candidate who comes up short in a major-party primary from switching to a minor party for the general election. That statute was originally written in a way that was a little murky, and an amendment clarifying its intent was signed into law in March but did not take effect until early June—a month after Blankenship lost the GOP nomination to state Attorney General Patrick Morrisey. According to Blankenship, using the new language to block his campaign would be a move fit for Adolf Hitler or Joseph Stalin.

“This is what the Communist or Nazi party would do and is a perfect example of political party behavior that violates an American’s guaranteed right to equal opportunity,” his campaign said in a statement. That kind of persecution-minded bombast is on brand for Blankenship. He claims, for instance, that his recent stint in prison for his role in a deadly mine disaster made him a “political prisoner” of the Obama administration, and he has paid for ads alleging that it was federal regulators who were really to blame for the blast, which killed 29 men.

Senate Republicans were terrified that if Blankenship had become their nominee, he would have spoiled their chances of defeating Manchin. Trump won West Virginia by more than 40 percentage points two years ago, and another Republican victory there this November would seriously hamper Democrats’ attempt to retake the Senate this fall. Should he make it on the ballot on a third-party line, the wealthy Blankenship is a real threat to siphon off some small but significant support from Morrisey, in a race where a percentage point or two could make the difference.

Mitch McConnell had originally hoped his party could just ignore Blankenship, but he emerged as a contender in the GOP primary by casting himself as a politically incorrect outsider willing to take on the Washington establishment—by suggesting, for instance, that McConnell was some sort of drug kingpin and by taking blatantly xenophobic swipes at his Taiwanese-born wife, Transportation Secretary Elaine Chao. McConnell’s allies eventually attempted some not-so-subtle subterfuge to derail his campaign, and Donald Trump ultimately got involved, too. McConnell was so happy when Blankenship lost the primary that he celebrated with some photo-shopped cocaine. There’s been no word on how the Senate majority leader is handling Blankenship’s attempted return.