This essay first appeared on September 24, 2026 in Law & Liberty.
Since the early days of the American Republic, political parties have been vehicles through which people of modest means can participate effectively in politics. Like churches, families, associations, and corporations, parties are mediating organizations between the individual and government.
And like other mediating organizations, parties have come under fierce attack from the left. One form of attack has been promotion of state election laws allowing non-party members to vote for party nominees.
But on June 30, the Supreme Court issued a case that brought it one step closer to ruling that such laws violate the Constitution’s First Amendment, as incorporated against the states by the Fourteenth. The case was National Republican Senatorial Committee v. Federal Election Commission (hereinafter National Republican).
Party Primaries Explained
In the traditional closed party primary, party members vote on which candidates to nominate for the general election. But fourteen states require open primaries, which permit all electors—even those belonging to hostile parties—to vote in any party’s primary. The Republican Party of Texas has launched a lawsuit challenging that state’s open primary law.
Ten other states mandate semi-closed primaries, also called semi-open primaries. (We’ll use the latter term.) These allow unaffiliated electors to vote in any party’s primary. The Republican Party of Colorado has filed a lawsuit challenging that state’s semi-open primary law. In that case, a federal district judge gave the Republicans a partial, but significant, victory—although in further proceedings his conduct has been painfully slow.
Of course, these laws are different from those that permit, but do not require, parties to conduct open or semi-open contests. The latter do not suffer from the same constitutional difficulties.
Reasons for Open and Semi-Open Primaries
Open and semi-closed primary laws have been around for some time. However, in recent years they have proliferated, promoted mostly by center-left organizations.
The most salient stated goal for promoting these laws is to favor “moderate” candidates who “appeal to a wider portion of the electorate” over more “extreme” and “partisan” candidates. The promoting organizations contend that parties must accept such restrictions in exchange for state financing of primary elections. Constitutional wonks may recognize that the latter argument disregards the Supreme Court’s unconstitutional conditions doctrine: A state may not force you to give up a constitutional right in order to receive a government benefit.
I suspect that the sponsors’ primary goal is to affect GOP primaries. Outside a few regions where socialists can win intra-Democratic Party races, most Democrat primaries display few real policy differences. It is in Republican contests where the real debate happens. The goal of the promoters seems to be to prevent strongly conservative or government-cutting candidates from getting to the general election ballot—or, if they cannot prevent that, to force those candidates to temper their message.
An instance of the latter effect recently came to light in the Colorado lawsuit, where several Republican candidates asked the court not to mandate an immediate change back to a closed primary because they had fashioned their nomination campaigns for an electorate that included liberal independents as well as Republicans.
Previous SCOTUS Decisions
In a November 6, 2025 Law & Liberty essay—written well before the new SCOTUS decision in National Republican—I contended that open and semi-open primary laws were likely unconstitutional. Here’s why:
In considering the validity of a state election regulation under the First Amendment, the Supreme Court initially determines whether the regulation imposes a “severe” burden on First Amendment freedoms. If the burden is not severe, the rule survives if it serves “important regulatory interests” (a form of intermediate scrutiny). But if the burden is severe, the court subjects the regulation to strict scrutiny: The state must demonstrate that it is necessary for promoting a compelling state interest (or compelling governmental purpose).
Two cases illustrate the constitutional problems inherent in open and semi-open primary laws. The first is Democratic Party v. Wisconsin ex rel. LaFollette (1981). There, the Supreme Court reviewed a Wisconsin measure that required each Wisconsin delegate to a national party nominating convention to vote for the winner of a previously held open state preference primary.
Writing for his colleagues, Justice Potter Stewart acknowledged that the Democratic Party’s right of association included the prerogative of excluding non-members from its decision-making processes. He found no relevant compelling state interest to support the measure, and ruled it unconstitutional.
In California Democratic Party v. Jones (2000), the court examined California’s partisan blanket primary law. A partisan blanket primary is a version of an open primary, where instead of the elector choosing a single party for the particular election, the elector may enter a different primary for each office on the ballot.
Justice Antonin Scalia wrote the opinion for the court. He affirmed that “a corollary of the right to associate is the right not to associate.” He added that because of the central role nominees have in promoting the party’s message and obtaining political power, “In no area is the political association’s right to exclude more important than in the process of selecting its nominee.” As for the California law’s goal of changing the parties’ message, “We can think of no heavier burden on a political party’s associational freedom.”
Justice Scalia next inquired whether the purposes behind the blanket primary law were “compelling.” He ruled that favoring moderates or centrists over alleged “extremists” is not a compelling state interest—or even a legitimate one. He also dismissed as non-compelling (1) the wish of non-party members to vote in the primaries of parties they refused to join and (2) the minimal reduction of privacy entailed in registering with a party. As for the law’s purported goal of promoting fairness, Scalia wrote that excluding non-members “seems to us less unfair than permitting nonparty members to hijack the party.”
National Republican Senatorial Committee v. Federal Election Commission
On June 30, the Supreme Court issued its decision in National Republican. The decision addressed the constitutionality of federal limits on expenditures coordinated between a candidate and his party. It ruled that those limits violated the First Amendment and overruled a 2001 case holding that they did not.
Although National Republican did not address primary elections, much of its language is relevant to that subject. National Republican demonstrates that the Court remains committed to the values expressed in the Jones case, and perhaps even more so.
Justice Kavanaugh began the relevant part of his opinion by observing that “The First Amendment’s protection of free speech has its ‘fullest and most urgent application precisely to the conduct of campaigns for political office.’” To address the severity of the campaign expenditure restrictions at issue, “one must first appreciate the important and traditional role of political parties during campaigns.”
That role, he wrote, consists of three functions:
- Parties “articulate policy positions and platforms,”
- they select candidates by primary or caucus, and
- they support their candidates in general election campaigns.
Justice Kavanaugh then explained how the limits on coordinated expenditures severely impaired the ability of parties to perform the third of these functions. As Justice Scalia did in Jones, he next examined the purposes behind those limits to see if any were compelling.
In defense of the limits, the government offered four purposes. Justice Kavanaugh accepted only one as compelling: preventing actual or apparent quid pro quo corruption. As Justice Scalia did in Jones, he specifically rejected the principal stated goal of those advocating open and semi-open primary laws:
“Nor may Congress restrict campaign spending so as to level the electoral playing field, or to enhance or diminish the relative influence of certain groups or views. … The ‘concept that government may restrict the speech of some elements of our society in order to enhance the relative voice of others is wholly foreign to the First Amendment.’”
He also recognized that government restrictions on political parties have done much damage. In particular, they have facilitated the rise of billionaire-funded “dark money” PACs:
“Since 2001, political parties’ relative power has substantially diminished in comparison to outside groups. … The political-party coordinated-expenditure limits impose a “stifling effect on the ability of the party to do what it exists to do.” … Meanwhile, donors can and do send their funds to Super PACs and other outside groups that have a First Amendment right to receive and spend unlimited money to support their independent political speech. … In the 2024 election cycle, PACs raised over $15.7 billion, as compared to $2.7 billion by political parties. …
“To uphold the political-party coordinated-expenditure limits here could therefore help consign political parties to continued second-tier status as compared to outside groups. Weakened political parties distort the political system. And in the views of many, the relatively diminished political parties have ushered in increased political polarization and fragmentation.”
Thus, Justice Kavanaugh recognized that government intervention has helped create the very polarization cited as a reason for government infringement of political parties’ right of free association.
In conclusion, National Republican and the cases challenging open and semi-open primaries—such as those now proceeding in Texas and Colorado—all address laws burdening parties’ core functions.
To be sure, they are different core functions: National Republican dealt with the function of candidate support, while challenges to open and semi-open primaries address candidate selection.
But it is difficult to see why the difference should matter—particularly since, as Justice Scalia wrote in the Jones case, “In no area is the political association’s right to exclude more important than in the process of selecting its nominee.” In other words, candidate selection is at least as important as candidate support.
So consistent application of the principles enunciated in National Republican should render open and semi-open primaries unconstitutional.