Donald Trump has yet to be nominated for the presidency, but Republicans are already looking for ways to prevent another candidate like him in four years’ time.

Politico reports that Ted Cruz’ delegates — who are still pledged to support the Texan at the convention even though he has dropped out in Trump’s favor — are pushing for reforms that would restrict the nominating process to Republicans only.

Trump, who wasn’t a Republican until a few years ago, did well in so-called open primaries, when non-Republicans can vote. Cruz, a hardline conservative, did better in closed primaries, when only registered Republicans participate.

“Trojan horse”

“We now have a progressive, Trojan horse candidate that manipulated the open primary process to hijack the [Republican] nomination,” Kendal Unruh, a Colorado party activist, said of Trump.

Unruh will join the rules committee at the Republican National Convention in Cleveland, Ohio this summer; the conclave that sets the terms for the next presidential campaign.

Her fellow committee member from Colorado, Guy Short, agreed, telling Politico, “I think we need to start punishing states that have open primaries. If you’re not a Republican, then you can wait for the general.”

Fear of purists

National party leaders have long resisted limiting voting to registered Republicans, fearful that such a contest would produce an unelectable purist — like Cruz.

But Trump has convinced some that the alternative is worse.

“I believe that only Republicans should vote in Republican primaries,” Republican National Committee chairman Reince Priebus said last week, before emphasizing that the decision is up to the states.

Henry Barbour, Mississippi’s national committeeman and a 2012 rules committee member, also said, “We’re a bottom-up party. And the last thing that we need is the national party trying to tell us … how we’ve got to run our primaries.”

States’ rights

Unlike political parties in Europe, America’s are highly decentralized. The party platform and presidential candidate are decided every four years by representatives from the states: the delegates. The national party, chaired by Priebus, has little power.

The state parties decide for themselves how they elect their delegates. They can hold caucuses or primaries; they can use a proportional or a winner-takes-all system.

And they zealously defend that independence.

When the 2012 national rules committee proposed rewarding states that hold closed primaries with a 10-percent delegate bonus, it was rejected as too coercive.

A new proposal this year is to move closed primaries up to the front of the nominating calendar.

Now the open primaries of New Hampshire and South Carolina, which vote second and third, can have an outsized influence on how the contest progresses.

Trump won both contests this year, forcing more mainstream candidates like Jeb Bush and Chris Christie out of the race.