There are a slew of congressional candidates gunning to appear on Colorado’s ballots for the June 25 primary, the contest that will determine who makes it to the general election in November.

With three open GOP seats – in congressional districts three, four and five – many ambitious Republicans in particular see this as the year they could potentially make it to the U.S. Capitol.

But to get that chance, they first need to secure a spot on the primary ballot, and that’s not guaranteed. Colorado offers two different paths to qualify: candidates can try to win enough support at party gatherings, or they can scour the district for petition signatures. Both routes offer benefits, and challenges.

This spring both major parties will hold district assemblies in each of Colorado’s eight House districts. Delegates at those gatherings, generally grassroots activists and other active party members, have the power to nominate candidates for the primary election ballot.

A candidate must get 30% of the vote at a congressional district assembly to make it on the ballot.

The process requires a strong ground game for candidates, especially as they try to win over party insiders and activists. In a crowded race, it can also net you topline on the ballot, which goes to the candidate who gets the most votes at the assembly.

Congressional assemblies are happening around the state from now into April. The whole process culminates with the Republican State Assembly on April 6 and the Democratic State Assembly on April 13.

For a congressional primary, a campaign must collect either 1,500 valid signatures or 10% of the total number of votes cast in the last general election for that seat, whichever is smaller. For minor party and unaffiliated candidates, the percentage total drops to 2.5%.

Candidates can use volunteers, but many pay to collect signatures, so this approach can be costly. There are a lot of rules and regulations around what’s considered a valid signature (correct full name, address for where the voter is registered, etc.), so most campaigns try to submit more than required number because a percentage will often be considered invalid.

And while there’s no rule against voters signing more than one petition, each person’s signature can only count once. So candidates have a motivation to get their petitions in quickly, before people who have signed them get claimed by another campaign.

Petitions were due to the Secretary of State’s office on March 19.

Yes, candidates can and do sign up for both options. But it comes with risks; a candidate who does both must get at least 10% at the assembly in order to get on the ballot, no matter how many signatures they collect.

For those going the assembly route, GOP political consultant Dick Wadhams said, “you’re dealing with the most active, most interested, and, in many cases, the most ideological members of a political party.”

That dynamic means it’s the path that’s likely to advantage the most ideological candidates who appeal to the party’s base, while it presents a risk for moderates.

But it’s also the more cost-effective way to get on the ballot. Campaigning, Wadhams said, usually “consists of one-on-one meetings, phone calls, small group meetings … You’re not spending a lot of money on voter contact because it’s a fairly limited group.”

And winning over delegates can have long-term dividends. These are people who are deeply invested in the party and the race, making them more likely to donate and turn out on Election Day.

On the flip side, the assembly process really limits the number of people who can make it onto the ballot. With a 30% requirement, no more than three candidates can qualify through this route.

The petition process can potentially lead to a very crowded primary ballot, so long as candidates meet the required number of signatures. That however can be a laborious and costly process, with many campaigns hiring professionals to go door-to-door or stand outside at businesses and events to collect signatures.

It also attracts a different type of voter. “You’re appealing to people who will be voting in the primary, [but] you don't get a lot of activists who are involved in the petition process … so you’re reaching a broader audience,” said Wadhams. It also means they might not be invested in a candidate’s campaign.

Wadhams said this could be why we’re seeing more candidates take the hybrid path to the ballot: both the assembly and the petition processes.

“They’re going through the caucus-assembly process. But as kind of a fail-safe, they’re also collecting signatures,” explained Wadhams. “They want to go through the caucus assembly process to appeal to activists, and yet they don’t want to leave that to chance and not get on the ballot. They want to go ahead and collect signatures in order to make sure they get on the ballot.”

On the Republican side, there’s one more reason candidates might seek out the assemblies this year. In the past, the state party was required to stay neutral in contested primaries. But the Colorado State GOP changed its rules last fall. Now the state party will remain neutral regarding candidates who go through the assembly process. That does not hold, however, for those who use petitions to get on the ballot.

To read more stories from Colorado Public Radio, visit www.cpr.org.