DENVER – With just days left in the legislative session, lawmakers continue to wrangle over how to establish a presidential primary in Colorado.

The Senate on Friday introduced its effort to transition away from a chaotic caucus system that plagued Colorado’s presidential nominating process and, in some ways, took the state off the map in terms of political relevance.

The Senate bill differs from an earlier House measure in that it would require unaffiliated voters to affiliate with a party to participate in the primary. If voters want to switch back to unaffiliated, they would have to request to do so.

The House bill would require temporary affiliation with a party, which would automatically default back to unaffiliated after 30 days.

“It’s a system which we’ve outgrown,” Sen. Lucia Guzman, D-Denver, a co-sponsor of the Senate bill, said of the presidential caucus. “I think this is a good opportunity to begin to look at a presidential primary election process ... in the hopes that it will provide much more opportunities for more folks to get involved.”

But having two competing pieces of legislation complicates things. Added to the confusion is a proposed ballot initiative in which all voters would receive a mail ballot without having to choose a preference.

“It appears we’re headed for a ... stalemate on this issue,” said Sen. Pat Steadman, D-Denver. “There’s competing bills with different features, and I don’t think that there’s really been the work that’s been necessary between the two chambers and the two parties to resolve this this year.”

Meanwhile, ballot proponents say they haven’t seen a legislative solution that would stop them from forging ahead with an initiative.

“It’s not fair to ask 1.4 million independent voters to pay for an election from which they are intentionally excluded,” said Curtis Hubbard, spokesman for the ballot effort. “We expect broad support for our efforts to open not just a presidential primary but all primaries to Coloradans who want their voices heard.”

The plans would not do away with the state’s caucus system, in which neighbors gather to voice their support or opposition to a candidate as part of a grass-roots nominating process. Those caucuses would take place for other offices, such as legislative races.

Meanwhile, funding remains a concern, with the price tag as high as $5.5 million. Lawmakers say they don’t have to worry about finding money this legislative session, as they’ll have several years before the 2020 presidential election.