This story is part of CT Mirror Explains, an ongoing effort to distill our wide-ranging reporting into a "what you need to know" format and provide practical information to our readers.

Connecticut’s Democratic primary election in 2026 could become uncharacteristically competitive, with several well-known incumbents drawing potential challengers for their seats.

Gov. Ned Lamont, who is expected to launch his run for a third term as Connecticut’s chief executive, watched this summer as Josh Elliott, a progressive Democratic legislator, announced plans to primary him.

Meanwhile, more than four Democrats — including former Hartford Mayor Luke Bronin and state Rep. Jillian Gilchrest — have announced plans to try to unseat U.S. Rep. John Larson, who has represented Connecticut’s 1st Congressional District for nearly three decades.

Many of the would-be challengers are already honing their messages and raising money in preparation for what could become bruising political battles.

But just because someone announces a campaign on social media doesn’t mean they will be in contention during the primary next August.

In Connecticut, political candidates — especially those challenging sitting incumbents — need to clear several hurdles just to have their name listed on the ballot.

Here is a look at how parties choose their candidates and the steps challengers need to take to qualify for a primary.

How do candidates make it onto a primary ballot in Connecticut?

There are several ways for statewide or congressional candidates from a major party to make it onto a primary ballot in Connecticut.

The two easiest paths run through the political party conventions, which are gatherings of top Democratic or Republican officials.

Anyone seeking a statewide office or a congressional seat will have their name added to the primary ballot if they receive enough support from the convention delegates, who get to vote on which candidates the party should endorse.

The person who wins the party endorsement automatically gets onto the ballot.

But Connecticut’s election laws specify that any candidate who also receives at least 15% of the votes during a round of balloting at the convention will automatically qualify for the primary. That means challengers can make it onto the ballot even if they don’t receive the party’s stamp of approval.

For those who don’t get a spot on the ballot at the conventions, the third way to throw their name into contention is to petition their way into the race by collecting enough signatures from eligible voters to qualify for a primary race.

When are the conventions and who are the delegates?

The statewide party conventions in Connecticut, where delegates vote to endorse candidates for governor and other statewide offices, are held in the spring ahead of the party primaries in August.

The same is true for the congressional conventions, which are separate events where party delegates from each of the five congressional districts in Connecticut choose who will serve as the party-endorsed candidates in primaries for the U.S. House.

The delegates at those conventions are made up of Democratic and Republican party members from each of Connecticut’s 169 towns and cities, and it is largely up to the local Democratic and Republican town committees and the local party chairs to determine who those delegates are.

The delegate selection process is one of the reasons that critics argue the system is set up to benefit party insiders and tamp down political upstarts.

If you succeed at the convention, you can begin to campaign instead of spending money and time collecting signatures.

What happens if candidates fall short at the convention?

If a political candidate can’t rally enough support from the party insiders at the convention, there is another way to keep their campaign alive. But the road to the primary gets a lot harder for those people.

That’s because candidates who are snubbed at the convention need to gather thousands of signatures from voters who are registered with their political party.

Connecticut law requires candidates for governor and congress to obtain signatures from at least 2% of registered party members in the state or in their congressional districts in order to qualify for the ballot.

In a Democratic primary for the 1st Congressional District, for instance, that threshold would currently require candidates to collect roughly 3,700 signatures. And in a Democratic gubernatorial race, it would obligate a petitioning candidate to secure roughly 15,800 signatures from registered voters, based on current voter registration numbers.

The bigger hurdle, however, is the timing of those signature drives. The law specifies that petitioning candidates have just 42 days to pound the pavement and collect all of the necessary signatures.

What does a petitioning candidate need to do?

Plenty of candidates have shown that it is possible to run a successful primary campaign without the support of their party’s delegates.

Bob Stefanowski, for instance, gathered more than 9,000 signatures from Connecticut Republicans in 2018 in order to qualify for a crowded gubernatorial primary that year.

Today, the 42-day window would require a potential Democratic gubernatorial challenger to collect more than 370 signatures per day from registered Democrats, based on current voter registration numbers.

State law requires those signatures to be collected in-person by people who are registered in Connecticut with the correct political party.

And when the signature drives are done, the petitions need to be notarized and turned over to the registrars of voters in multiple towns for each signature to be verified.

That means that some signatures can be tossed if the people who signed the petitions are not properly registered with the party, or if there are duplicate signatures.

All of that sets up a hectic month-and-a-half-long race for petitioning candidates to earn their spot on the primary ballot.

What are the arguments for and against the ballot access laws?

Supporters of Connecticut’s ballot access laws argue that the current rules enable the two major political parties to vet the candidates who are going to be running for office under their banner. The rules also ensure that anyone who makes it onto the ballot has a least a nominal level of support from party members.

Critics of the system, however, argue the state’s laws only serve to empower party insiders and to protect incumbent politicians from potential challengers.

Each state has their own unique requirements that specify how candidates can place their names onto primary ballots. Many states, for instance, allow people to make it onto the primary ballot simply by paying a filing fee.

Opponents of the system in Connecticut have argued repeatedly that the state’s rules for ballot access are some of the most restrictive in the country.

Muad Hrezi, who attempted to challenge Larson in a 2022 primary for the 1st Congressional District, made that very argument in state court after he failed to gather enough signatures to advance his campaign that year.

A state superior court judge overseeing that case, however, rejected the argument that the state’s laws were overly burdensome and unconstitutional. And the judge noted that a Republican candidate in the state’s 4th Congressional District that year was able to collect enough signatures to petition their way onto the ballot.

To be sure, the state’s laws on ballot access have become slightly easier for challengers to meet due to legislative changes and court rulings in past decades.

Even so, no one has ever qualified for a primary in Connecticut against a sitting member of the U.S. House.