The Minnesota Supreme Court on Thursday rejected a voter challenge to a law that allowed the state Republican Party to list only President Donald Trump on GOP primary ballots.

In a case that threatened to disrupt next week's early primary voting, the justices upheld a state election law allowing state party chairs to pick who is — and isn't — included on presidential primary ballots. Early voting starts Jan. 17 for a regular primary election on March 3.

A three-page opinion signed by Chief Justice Lorie Gildea found only that a petition seeking to add the name of perennial candidate Roque "Rocky" De La Fuente lacks legal merit. The decision was rendered hours after oral arguments in the case, reflecting the need for state election officials to prepare and distribute ballots by the end of next week.

The law had been challenged by James Martin, a Minnesota voter from Lake Elmo, and De La Fuente, a California businessman and long-shot candidate seeking the 2020 Republican nomination for president.

"We're challenging basically a process that's made a mockery of democracy," said Minneapolis attorney Erick Kaardal, representing Martin and De La Fuente. "It's very sad that we're going to spend $12 million [in] March on the presidential primary and they're going to have only one candidate on the GOP primary ballot."

Martin and De La Fuente took legal action in October after the Minnesota GOP submitted a ballot to state election officials listing only Trump on party ballots.

Minnesota Secretary of State Steve Simon had sought an expedited decision on the challenge in order to prepare the ballots, but the high court denied an earlier hearing last month. Simon had said an overhaul of the ballots could cost "many thousands of dollars" to cover the cost of reprinting paper ballots and reprogramming automated voting systems that count ballots and help voters with disabilities.

Thursday's decision, however, let stand the ballots submitted by the GOP and DFL parties.

Kaardal called the proposed GOP primary ballot an unconstitutional effort to dictate the election's result. In arguments before the court, he repeatedly underscored that the elections are funded at taxpayer expense and should include all qualified candidates. Otherwise, Kaardal asked the justices, why would taxpayers foot the bill for an election that did not offer them a "meaningful vote"?

Assistant Attorney General Nathan Hartshorn, representing Simon in the case, acknowledged that the state Republican Party's decision to exclude other candidates amounted to a "political determination" to favor the president. But, Hart­shorn added, state parties have constitutionally protected free-association rights to choose who appears on presidential primary ballots.

The Minnesota DFL Party submitted a list of 15 candidates. Democratic officials also submitted briefs in the case defending the prerogative of party chairs to "define the process" by determining the makeup of their ballots.

The Minnesota GOP did not participate in the case, prompting Justice Natalie Hudson to note in Thursday's hearing that the party has been "conspicuous in its absence."

"We should be concerned because there is an absence of information," said Kaardal, himself a former state GOP party official.

Minnesota Republican Party Chairwoman Jennifer Carnahan has previously argued that her job as party leader is to help re-elect Trump. The Republicans have since formally requested a write-in option on their party ballot, but Kaardal argued Thursday that the party has not requested that Simon's office tally all write-in votes for candidates like De La Fuente. As it stands, Kaardal said, the office is required only to list how many total write-in votes were cast for all candidates.

Martin, the named voter in the challenge, said the GOP's move left him "being swept under the rug," adding, "I hope to be able to stand shoulder to shoulder with other Minnesotans expressing our opinions about what we believe our party should be putting forward to the national convention."

Hartshorn argued that the law seeks to protect against ballots becoming "cluttered" with a long "laundry list" ballot that includes frivolous candidates.

Some justices noted the length of the 15-name ballot submitted by the DFL. "Some might say it's even cluttered," Gildea said during the hearing.

The March 3 Super Tuesday primary is Minnesota's first presidential nomination primary since 1992. For the past six presidential nomination cycles, the state's major parties pledged their delegates to their respective national conventions based on straw polls held at local caucuses.

Kaardal said that De La Fuente is on primary ballots in about a dozen states. He has previously mounted unsuccessful bids for elected office — most recently in 2018 when he sought the GOP nomination for U.S. Senate races in nine states, including Minnesota.

Earlier this week Wisconsin Republicans also decided to limit their primary ballot options to Trump, freezing out other challengers like former Massachusetts Gov. Bill Weld and former Illinois Rep. Joe Walsh. Wisconsin Republican Party Chairman Andrew Hitt cited the other candidates' inability to get on primary ballots in other states as a reason for their exclusion on Wisconsin's ballot.

But at one point during Thursday's arguments, Gildea mused whether Minnesota's law governing who appears on ballots is appropriate.

"Isn't there something disturbing about the idea that the state could effectively control who voters can be allowed to vote for?" Gildea asked. "At the 50,000-foot level, isn't that disturbing?"

Stephen Montemayor • 612-673-1755 Twitter: @smontemayor