There’s a cynical old saying—often falsely attributed to Mark Twain—that if voting changed anything, it would be illegal. Over the past decade, Republicans across the country have tried to prove this aphorism right by passing a wave of restrictive voting measures at the state and local level. Those laws, combined with hardball tactics like partisan gerrymandering and certain structural advantages, helped entrench conservative rule over large swaths of an increasingly liberal America.

In November, Americans will have a chance to reverse that tide. The midterm elections are widely seen as a referendum on the Trump administration, and for good reason. But voters will also be weighing in on something even bigger than the president: the future of American democracy.

Trump looms large over this subject. His tone, temperament, and actions are more authoritarian than any of his predecessors. He’s sought to purge and take command of the Justice Department and federal law-enforcement agencies, claiming that they should be investigating his opponents instead of him or his allies. He openly sympathizes with foreign dictators while alienating longtime U.S. allies. And he’s contemptuous of the fabric of civil society, dismissing mainstream news outlets as “fake news” and claiming that protesters are paid agents of a Jewish billionaire.

Trump’s confidence in American elections hinges on a simple metric: the extent to which they personally validate him. When his poll numbers plummeted after the Access Hollywood tape surfaced in mid-October 2016, he repeatedly issued false and incendiary warnings to his supporters that the election would be rigged against him. Trump’s attacks quieted the moment he was elected president, only to start again when it became clear that almost three million more voters chose Hillary Clinton instead. “In addition to winning the Electoral College in a landslide, I won the popular vote if you deduct the millions of people who voted illegally,” he wrote on Twitter.

The Constitution’s framers anticipated that men like Trump might one day capture the presidency, and took steps to prepare for it. Their system of checks and balances, however, is effectively moribund under House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell. Congressional Republicans have largely used their oversight powers to shield the Trump administration from scrutiny, whether by not investigating obvious scandals or by using their powers to undermine investigations in other parts of the government. The House Intelligence Committee’s GOP majority spends most of its time these days trying to discredit the Russia investigation so that Trump can shut it down before it inflicts any more political damage.