Would an 'all-party primary' system give frustrated voters more 'mainstream' candidates?

Amid mounting frustration from centrist voters and shifting party coalitions, one group thinks it has the solution to making parties and political candidates: comprehensive election reform.

Unite America, a philanthropic venture fund, is in the middle of a yearslong effort to support ballot initiatives that would fundamentally alter the way candidates are elected. Rather than hold party primaries, some of which independent voters can't partake in, states would hold one large primary for all candidates for a race. Then, general election voters would be able to sift through winners in some form, including a ranked choice system or a competition between the top two vote getters.

In an interview with ABC News, Unite America Executive Director Nick Troiano said the system is intended to make the general election the race of consequence rather than low-turnout primaries in safe red or blue areas, making candidates accountable to voters of all stripes.

"If you're a candidate, the advantage is you're no longer only having to appeal to one side. You can talk to all the voters, and then all the voters can vote for whomever they want," Troiano said.

"It's really about trying to make the general election the election of consequence, meaning the primary, everybody can vote, everybody can run, but it winnows down to just a few candidates in a general election, when most people vote, should really be when the decision is made."

The reform movement is ramping up at a time of transformation for both parties. Democrats, smarting from Vice President Kamala Harris' loss, are looking to make a brand more palatable to working-class voters. And Republicans are expected to be tied even closer to President-elect Donald Trump after his win this month.

But the election reform efforts are coming off a rough election cycle.

Voters in Arizona, Colorado, Idaho, Montana, Nevada and South Dakota shot down ballot initiatives that would have instituted all-party primaries rather than contests grouping candidates of one party together. The effort marked a setback given rising conversations around other democracy-related issues like gerrymandering.

Troiano conceded the defeats, noting spending from both parties against the ballot initiatives and insisting that progress is not anticipated to be "linear." Unite America's advisors include those who worked on the marriage equality movement, which saw several states ban the practice in the 2004 election cycle but only to see same-sex marriage become federally legalized in 2015.

"Sometimes it's two steps forward, one step back. But that's how any movement that has made meaningful change in our country has worked. And so, we're disappointed but not deterred from this mission," Troiano said.

Some states already have versions of what Unite America is proposing.

Voters in 2022 implemented all-party primaries followed by ranked-choice general elections. Maine already has ranked choice voting. And other states like California and Louisiana institute so-called jungle primaries, which hold all-party primaries and then send the top two candidates to the general election if no contender hits 50%.

Rising independent voter registrations give Troiano hope that momentum will build for the reforms Unite America is pushing.

In the meantime, the group will conduct more research, link up with interest groups and push more ballot measures, Troiano said.

And, Unite America insists, both parties can benefit.

Democratic strategists have theorized that Harris lost this year's presidential race because of a brand that was viewed as too far to the left -- a reputation that could be confirmed by party primaries fueled by the most liberal voters. And Republicans have ceded ground in the suburbs, historically GOP power bases, with a reputation too firmly tied to Trump.

Democratic senators-elect who scored victories in Trump-won states were able to establish brands detached from that of the national party, and the only two Republican House members who impeached Trump left standing -- California Rep. David Valadao and Washington Rep. Dan Newhouse -- use all party primaries.

"I think both parties have a medium to long-term advantage in these reforms because it will help them nominate more mainstream candidates," Troiano said. "Both parties have a declining market share of the electorate as independents continue to grow, so it is to their advantage to think about ways to broaden their appeal."