The Utah Republican Party, however, requires those who vote in its primary to be registered members of its party.
While the law in question has allowed unaffiliated voters to join any party at the polls, it did not allow people already registered in a party to switch on Election Day.
Utah law allows voters to switch party affiliations anytime, except for 30 days before an election when all voter registration temporarily ceases. So if the current law expires, unaffiliated voters wishing to vote in a GOP primary would have to register as Republicans at least 30 days before the election.
Some Republicans have complained for years that members of other parties or unaffiliated voters could raid their primary to defeat stronger candidates.
However, Sen. Margaret Dayton, R-Orem, said that is not why she made the motion to allow the law to expire, or "sunset." She said that law "applied only to unaffiliated voters. So by allowing it to sunset, we put all voters in the same category."
House Democratic leader David Litvack, D-Salt Lake City, moved to extend the current law for another five years. He said many unaffiliated voters are true independents who still want some influence on the ballot, and are not attempting political subterfuge by joining a party on Election Day.
"To make it more difficult for them to participate is not the way to go," he said.
The motion failed on a near party-line vote.
Rep. Kraig Powell, R-Heber City, the House chairman of the committee, was the only Republican to vote with Democrats to extend the current law and said he was surprised that fellow Republicans voted so lopsidedly to let the current law disappear.
Allowing unaffiliated voters to switch on election day "is pretty much a fixture in Utah election psyche right now," Powell said. "Taking away their ability on the Primary Election Day to show up, affiliate and then vote closes them out of a substantial portion of our election process."