Sixteen years after the Supreme Court ruled in Citizens United v. FEC that corporations have a First Amendment right to spend money to influence elections, Montana voters will decide in Tuesday's midterm elections whether their state can take that power away.

Initiative 194, also known as the Montana Plan, would strip corporations, trade associations, nonprofits, and other organizations of the legal power to spend money supporting or opposing a political candidate or ballot initiative in Montana. Backers say they have found a way around Citizens United, while critics argue the measure's legal framing still violates the 2010 Supreme Court ruling.

Rather than banning corporate political donations outright, I-194 would alter the powers Montana grants to corporations and other entities the state refers to as "artificial persons," limiting them to only those powers that are "necessary and convenient."

The measure would apply to entities that do business or hold property in Montana, but exempts political action committees (PACs), news and editorial content, and individuals. Organizations that violate the restriction would forfeit the privileges Montana grants them to do business in the state, including limited liability, which protects owners from personal responsibility for business debts.

A way around Citizens United

At first glance, the language of the ballot initiative appears to contradict what Citizens United established—that corporations can spend money on elections. But Tom Moore, a former chief of staff to FEC Commissioner Ellen Weintraub who is now a senior fellow at the Center for American Progress and who devised the legal theory behind the Montana Plan, told Fortune that states hold authority over what corporations can do through corporate law.

"When the state creates a corporation, it is starting from nothing and deciding what to give the corporation, and no case has ever held that they have to give local spending power to a corporation," Moore said.

Under that reasoning, I-194 would simply stop granting corporations and nonprofits the ability to spend money on elections, which Moore said differs from banning them from exercising an existing right. "It's not regulation; it's redefinition," he said.

Moore said he believes the measure would shut down dark money spending by preventing wealthy donors from hiding behind organizations that do not disclose their contributors. Under current practice, a donor can give money to a nonprofit that then funnels it to a PAC, which reports the nonprofit as the donor rather than identifying the individual. Moore said I-194 would cut off that route by preventing corporations, nonprofits, and trade associations from political giving, though individuals can still donate.

"This is not going to stop Elon Musk from writing a big fat check to some election in Montana," Moore said. "What it will stop them from doing is laundering the money through a dark money group."

Opponents of the ballot measure, however, say the distinction between barring corporations from political giving and infringing on their political rights is blurry. Bradley Smith, a former FEC chairman and professor at Capital University Law School, told Fortune that states cannot sidestep the First Amendment by calling political spending a corporate power instead of a right.

"The Supreme Court isn't engaged in a semantic game," he said.

Smith said states can set rules for corporations, but they cannot make them surrender constitutional protections in exchange for the benefits of incorporation.

"The core centerpiece undoubtedly is we're going to deny all corporations in the state the right to speak about political affairs and about political candidates, and that's just going to fail," he said.

Montana's century-old fight against corporate interests

Montana has tried curbing corporate influence in elections before. In 1912, Montanans passed the Corrupt Practices Act by initiative with 76% of the vote, angered by the political power of mining giant Amalgamated Copper and by the state's mining magnates, known as the Copper Kings, who had bribed state legislators years earlier. The law barred corporations from spending money to influence elections and stood for a century before the Supreme Court struck down the restriction in American Tradition Partnership v. Bullock in 2012, ruling that it conflicted with Citizens United.

Montana is also not the only state trying to limit corporate influence over elections. Hawaii enacted a law similar to I-194, called Act 11, in May. That measure now faces two federal lawsuits: one from the U.S. Chamber of Commerce and another from the Grassroot Institute of Hawaii, which the Institute for Free Speech, an organization Smith founded, represents. The cases could help decide whether states can use corporate law to restrict political spending despite Citizens United.

Moore expects the issue to go up to the Supreme Court, whether through I-194 or the Hawaii lawsuits. If voters approve I-194, it would take effect Jan. 1, 2027, unless a court blocks it.

This story was originally featured on Fortune.com.