DENVER — Colorado Republican leaders on Saturday voted down an attempt by party activists to cancel the 2018 primary in order to prevent participation by unaffiliated voters.

State voters last year approved changes that allowed Colorado’s 1.4 million unaffiliated voters to cast ballots in either the Democratic or Republican primary. The changes also included an “opt-out” provision that allowed for canceling primaries if the vast majority of a party’s leaders agree.

In Saturday’s vote, 67 percent of the Republican central committee voted to stick with the primary system, versus 33 in favor of opting out, Republican Party spokesman Daniel Cole said.

Party leaders also agreed to revisit the issue in two years, he said.

The vote came after some Republicans activists said only party members should be able to participate in candidate selections, so that those chosen would better reflect GOP values.

But most party leaders and Republican elected officials said barring unaffiliated voters would hurt their chances in the general election because those voters would gravitate toward Democrats, Cole said. “The unaffiliated voters would have started to develop bonds of loyalty to these Democratic candidates because they’d be able to vote for them in the Democratic primary,” he said.

Rank-and-file Republicans who supported the use of a primary also could have been alienated if next year’s primary were cancelled, Cole said.

Unaffiliated voters represent the biggest voting bloc in Colorado. The state’s two major parties have about 1 million voters each.

Ben Nicholas, a Republican local district captain in Adams County who helped lead the effort to cancel next year’s primary, said he doesn’t expect to press the issue again until after the outcome of next year’s election.

“This is an experiment that is now going to have to run its course,” he said. “If it’s an absolute disaster, I will be proven correct that we should have opted out.”

Before last year’s change, both parties in Colorado followed an unusual process for selecting nominees. There were two paths to a primary ballot – collecting sufficient signatures to land on the ballot or being placed there by winning a majority vote at the party’s annual assembly, a daylong gathering of its most motivated few thousand members.

The assemblies were criticized as baroque proceedings that favored the most motivated activists and can lead to the nominations of candidates who can’t win a general election.

Last year, Sen. Ted Cruz was crowned as the GOP’s preferred candidate in Colorado’s Republican Assembly because the Texas senator’s campaign placed a priority on organizing among the hundreds of local caucuses that determine which activists can attend the assembly. Donald Trump and his supporters said the process was rigged.