The upcoming primary season in Maine is ushering in yet another innovation in the way the state chooses the party candidates who will appear on the general election ballot. The change now allows voters who aren’t enrolled in a political party to vote in party primaries without having to enlist as a party member.

Until this year voters have been required to register in the party whose primary they wished to vote and were locked into that party affiliation for the following three months.

It’s a change that is one of many that have significantly altered the system since its adoption in 1911 and an occasion to take a glimpse at how other states engage in the same winnowing out process.

The primary system – that is one in which all voters in a political party get an equal vote in who will run in the general election – has been around so long and is so prevalent in America we take it for granted.

We shouldn’t, however.

For one thing, the United States still stands alone in the entire democratic world for allowing direct voter participation in these crucial semi-final contests. Elsewhere, whether England, France, Germany or Canada party meetings or caucuses mandate the general election choices. Such was long the case throughout this country.


In Maine, for example, caucuses and conventions of a small percentage of voters deemed delegates designated the nominees. The process was done so openly that it offered the advantage of transparency.

However, those participating were perceived to be vulnerable to the influence of party bosses and other hierarchal forces. Such a system prevailed until the early 20th century when Wisconsin in 1903 adopted the first comprehensive state-wide primary law. Over 20 states soon did so by the time Maine voted to go the same way in a citizen initiative referendum in 1911.

It was a logical extension of the 1891 Maine law by which the state adopted the secret ballot method for voting in its general elections. It was also a precursor to the expansion of voter participation made possible by the nation’s 19th amendment guaranteeing women the right to vote.

All states and the District of Columbia now embrace a system that affords voters the prerogative of nominating candidates at the state and Congressional level. (Five states including Iowa and Missouri retain the caucus system at the Presidential level.)

We still have dramatically different systems, however. Indeed, some have virtually abandoned the concept of a partisan – that is party dominated – method altogether.

Nineteen states – including such ideologically diverse jurisdictions as Vermont and Texas – have no requirement of party affiliation as a condition for voting in their primaries. That’s due largely to the fact that none of them even allow enrollment in a political party as part of their registration process.


One’s own personal party preference is thus completely private. Though voters in these states can vote in only one party’s primary at a time they can choose any party they want on the spur of the moment.

California and Washington state have also dimmed the parties roles. Each of them in recent years has embraced the “top two” primary. This means that the two leading candidates – regardless of party affiliation – advance to the general election. This often results in two nominees from the same political party squaring off against each other.

Alaska in 2020 adopted a variation of this when it chose to have the top four move on to the general election. At the same time Alaska also became only the second state – after Maine – to adopt ranked choice voting if none of the four wins a majority.

Louisiana for nearly a half century has also preempted the party nomination process. In the Bayou state there are no primaries – except for presidential ones. There is just one general election. A run off ensues only if the winner falls short of 50 percent of the vote.

A run off then determines the winner. The state will be backing off somewhat from such a system in 2026 under a law passed in late January that will restore closed partisan primaries for Congress and some of its state-wide state offices.

State legislators in Nebraska run without party affiliation in non partisan elections. This is the same system most states including Maine has for nearly all of its cities for municipal offices though in both states partisan primaries are retained for other state and Congressional elections.


Fourteen states including Democratic New York and Republican Florida along with such battleground states as Pennsylvania and Nevada have closed primaries, meaning voting is restricted to only those enrolled in the same political party as the party in whose primary they are voting.

Maine is one of three states – the swing states of Colorado and Arizona being the other two – deemed semi-open.

“Semi-Open” means that a state allows those regardless of affiliation to vote in any party they want but subject to certain guardrails that limit their ability to do so. In Maine this now means that:

A) Any non party voter or “independent” can vote in either primary but:

B) Any member of an opposing political party can only do so if he or she changes enrollment 15 days or more before the primary;

It’s the 15 day rule then that keeps the state from being a completely “Open” primary state.

To be sure, the path to getting on to a general election ballot is not necessarily through a primary – just ask Independent US Senator Angus King – but it is still the predominant means of getting there.

How Maine got to the equivocal designation of a “Semi-Open” primary state is an intriguing journey and the subject for a future column.

Paul Mills is a Farmington attorney well known for his analyses and historical understanding of public affairs in Maine. He can be reached at

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