An earlier version of this op-ed incorrectly stated that the South Dakota legislature repealed a ballot initiative on campaign finance and political corruption in an emergency session. The measure was passed in regular session under an emergency clause. This version has been updated.

Josh Silver is founder and director of Represent.Us.

Less than a day after voters in Maine voted to expand Medicaid in their state, Gov. Paul LePage (R) moved quickly to subvert their democratic will, announcing Wednesday that he will not implement the expansion until it is "fully funded by the Legislature."

This is not the first time that elected officials in the state have blatantly ignored voters in this way. Last year, Mainers approved an innovative reform known as "ranked-choice voting," as an effort to ensure that their governor wins with a majority of the vote. But the state legislature did not agree with that decision, so it recently voted to delay and potentially repeal the initiative. In fact, it brazenly meddled with every single ballot measure passed by the state's voters in 2016.

The news out of Maine is part of an ominous pattern: state legislators across the country resisting the will of the people by gutting or even repealing citizen initiatives. This is a shockingly undemocratic trend at a time when U.S. voters are already deeply unsatisfied with their elected leaders.

The citizen initiative — in which a group of voters brings a proposed law or constitutional amendment to the ballot for the public to approve or reject — exists in 26 states and the District. It has long been a critical tool for advancing key issues that are popular with the public but unlikely to make it through legislatures or city councils.

But more and more legislators have been willing to effectively deny their constituents' political voices. Perhaps the most egregious repeal of a voter-approved initiative in modern history took place this year in South Dakota, where voters passed a suite of ethics and campaign finance reforms aimed at eradicating political corruption endemic to the state's politics. The state's legislature swiftly declared a legislative emergency and repealed the citizen-approved measure intended to regulate their own corrupt behavior.

Unfortunately, South Dakotans and Mainers are not alone. In Massachusetts, the legislature amended and delayed implementation of a 2016 voter-approved ballot measure to legalize marijuana sales. The Missouri legislature has repealed measures covering a range of issues, from school funding to gun safety to animal cruelty. Missouri lawmakers are also exploring new rules to make it harder to get an initiative on the ballot. Lawmakers in Michigan have the same objectives, but they employ different tactics. They have specialized in undercutting or superseding a proposed initiative before it has a chance to even pass — a process known as preemption.

And a year before the October massacre in Las Vegas, Nevada voters approved a ballot initiative to require background checks for gun purchases. A month later, the state's attorney general said the measure could not be enforced.

This pattern of legislative tampering should alarm all Americans. When our elected officials repeal voter-approved laws designed to improve the very nature of our democracy, it hurts voters from across the political spectrum.

Thankfully, there are better paths: In 1996, Arizona voters approved a measure to legalize medical marijuana by a margin of 30 points, only to have it gutted by the legislature the next year. Enraged, Arizonans went back to the ballot in 1998 to pass Proposition 105, which blocks politicians from meddling with voter-approved laws if legislative changes do not "further the purpose" of the measure. We also find hope in places such as California, where the legislature is completely prohibited from changing the text of an initiative that has been enacted by voters. Nebraska requires a legislative supermajority to change or repeal a ballot initiative.

Borrowing from these examples, we can support efforts to pass anti-tampering laws in the two dozen states that allow the initiative. We can advocate for supermajority requirements to amend or repeal any initiative, or better yet, we can forbid all tampering that fails to further the purpose of an initiative.

One such campaign, which my organization has led, has taken shape in South Dakota. Last week, grass-roots activists submitted more than 50,000 signatures to the secretary of state to place an amendment on the ballot. The proposal would finish what last year's now-overturned initiative started by restricting lobbyist gifts to politicians, creating an independent citizen ethics commission, making political bribery a felony and — perhaps most important — preventing the state legislature from changing any initiative unless that change is first approved by the voters.

If voters across the political spectrum can stand up in the face of this legislative resistance, they'll ensure that the true protectors of our democracy — the people themselves — have their voices heard in the fight against corruption.