The campaign to convince 75% of the Colorado GOP state central committee members to vote to opt out of open primaries picked up an endorsement from a former conservative legislator recently.

Kevin Lundberg, a former state legislator and director of the Republican Study Committee of Colorado, joins a conservative scorecard organization, and two state representatives in backing the effort.

Since February, grassroots Republican activists have lobbied to overturn Proposition 108 which voters approved in 2016, allowing unaffiliated voters to participate in major party primaries. The debate began on a conservative podcast, featuring a strident opt-out proposal by host and Colorado GOP executive committee member Chuck Bonniwell.

A counter-argument was provided by longtime GOP advisor, campaign consultant, former party chair, and establishment Republican, Dick Wadhams.

Now, six months later and with one month remaining before the GOP state central committee votes on the issue of whether to exclude unaffiliated voters from their primary, the debate has expanded, with more politicians, activists, and conservative organizations weighing in on both sides.

In addition to Lundberg, the conservative pundits and politicians endorsing the move to opt-out of open primaries include longtime Colorado conservative and former congressman, gubernatorial and presidential candidate Tom Tancredo; Rep. Dave Williams (R-El Paso County), Rep. Ron Hanks (R-Penrose), Colorado National Committeeman, Arapahoe Tea Party president, and conservative radio host Randy Corporon, and state chair of the Republican Liberty Caucus Sue Moore. Moore’s organization has also endorsed opting out of open primaries.

The original group of activists who organized the drive to opt out of primaries includes — apart from Bonniewell — GOP state central committee members Peg Cage from Boulder County, Anil Mathai and Ben Nicholas from Adams County, Jimi McFarland of the North Jeffco Tea Party, Joe Janecky from House District 35, and former Colorado House Minority Leader, Joe Stengle.

This group began their campaign in the spring, with an outreach and lobbying road tour, targeting county GOP executives and state central committee members from around the state. They have since expanded their efforts to include op-eds in online and print media, launching a designated website, and social media campaigns with explainer videos (see below).

Opponents to the opt-out effort, mostly represented by establishment Republicans, described by their GOP rivals as the “controllers, the big dollar folks, the consultant class, the moderate Republicans who want to get along and work with with Democrats for whatever selfish … reasons,” have generally stuck to publishing their own op-eds in legacy media platforms and providing comments for news stories on the topic.

Those who have publicly weighed in with their opposition include former prosecutor and candidate for attorney general George Brauchler, Colorado Senate Minority Leader Chris Holbert, House Minority Leader Hugh McKean, Rep. Colin Larson (R-Littleton), Sen. Barbara Kirkmeyer (R-Weld County), former President of the Colorado Senate Kevin Grantham, president of the conservative think tank Independence Institute Jon Caldara, former legislative candidate and Colorado Sun columnist Mario Nicolais, and GOP legislative campaign director and consultant Daniel Cole.

The anonymous conservative news blog, Colorado Peak Politics, published an editorial opposing the opt-out effort.

Republican officials who are not taking a position include Kristi Burton Brown, chairwoman of the Colorado GOP, who has pledged to stay neutral on the issue, and central committee member Bob Miles of Aurora, who is undecided.