In 2016, then-candidate Donald Trump complained that the primary process was rigged against him (it wasn’t). Now it’s President Trump’s turn to do the rigging. South Carolina canceled its first-in-the-South presidential primary, and Kansas, Arizona and Nevada are following suit.

Trump claims the states are canceling their primaries to save money. But with the deficit recently cracking $1 trillion, this sudden bout of fiscal conservatism seems dubious.

Republican leadership in these states say that there’s plenty of precedent for incumbent presidents not holding primary contests. That’s true, but there's no precedent for canceling a primary when there are already three announced GOP challengers: former Massachusetts governor Bill Weld, former Illinois representative Joe Walsh and former South Carolina governor Mark Sanford. South Carolina Republican Party Chairman Drew McKissick argues that these men aren’t “legitimate” challengers, but it's hard to make the case that two former governors and a former congressman shouldn’t be considered legitimate.

If there’s any point at all to primaries, it’s that the voters get to decide what kind of candidate is “legitimate” and what kind isn’t. In 2016, a plurality of Republicans decided that a former gameshow host with no political experience was “legitimate,” and the party honored their decision. If the voters want to change their minds now, party insiders shouldn’t alter the rules to stand in their way.

Trump claims the states are canceling their primaries to save money. But with the deficit recently cracking $1 trillion, this sudden bout of fiscal conservatism seems dubious.

Trump and the state parties can’t give a good reason why they want to cancel the 2020 primaries because the real reason is weakness. Three recent polls indicate that a fifth or more of Republican voters are already disenchanted with Trump — and Trump’s challengers have barely started to get their messages out.

A Boston Globe/Suffolk poll showed Weld with 17 percent support among likely Republican primary voters in New Hampshire. Another poll has him garnering similar numbers nationally. Considering Weld has run a relatively quiet campaign so far and there are now two other challengers in the race, the ranks of those choosing to back someone other than Trump have potential to grow.

Each of Trump’s opponents threatens him in a different way. Weld could win votes from socially liberal, libertarian-minded Northeast Republicans. Sanford, who represented South Carolina in Congress as well as serving as governor, might appeal to suburban Republicans with his message of fiscal restraint and responsible budgeting. Walsh, a full-time flamethrower (much like Trump himself), can attack the president from the populist right, pointing out that not a foot of border wall has been built, Trump isn’t standing up to America’s enemies, and the trade war has been a disaster for American farmers.

Maybe the only thing the three of them have in common (other than fiscal conservatism) is an ability to read polls. Trump is currently losing to five Democratic candidates head-to-head: Biden, Sanders, Harris, Buttigieg and Warren. The GOP trio aren’t crazy for thinking that Trump might not have the best shot at beating the Democratic nominee next year.

The party leadership owes it to voters to give them a chance to be heard. Trump’s acolytes cite the president’s high approval rating within the party (it’s not the 94 percent Trump claims, but recent polls only have him about 10 points lower)as confirmation that a primary is unnecessary. There’s a great deal of evidence, however, that a significant percentage of Republican voters are interested in considering alternatives.

A Hill-HarrisX survey conducted in June among registered voters found that 44 percent of Republican participants believed Trump should face a Republican primary challenger in the 2020 election.

When I conduct focus groups around the country for my organization, Defending Democracy Together, Republican voters often say they don’t regret voting for Trump in 2016 because they spared the nation the presidency of Democratic nominee Hillary Clinton. But when asked if they want another four years of Trump, they’re not so sure.

And count me among those thrilled to see some Republicans stepping up to challenge Trump. As a Republican opposed to Trump, I agree with Walsh that Trump is unfit for office. I agree with Sanford that Republicans have abdicated fiscal responsibility as a core principle. And I agree with Weld that our party needs to broaden its tent demographically if we’re going to be viable in the future.

It shouldn’t take a judge to tell Republicans in South Carolina — or any state — to do the right thing.

Legally, the South Carolina Republican Committee may have violated its own rules by canceling its primary. One or more of the candidates or voters will probably sue, hoping a court will order the primary to go on. But it shouldn’t take a judge to tell Republicans in South Carolina — or any state — to do the right thing.

Politically, party leadership is sticking its fingers in its ears and shouting “LA LA LA” to avoid reality. The news for them isn’t even that bad: Trump will almost certainly still be the nominee, and if the Democrats decide not to moderate their message, he could even win re-election.

None of that changes if primaries are held as normal. The only real risk is that party leadership and the president find out that party members don’t love him quite as much as he says.