State Rep. Dan Thurlow, a Grand Junction Republican, plans to announce Saturday he’s challenging state Sen. Ray Scott in the GOP primary, although he first considered running for the seat as an unaffiliated candidate, Colorado Politics has learned.

Thurlow, who has represented House District 55 for two terms, asked supporters in an email Friday to join him at 10 a.m. Saturday on the steps of the Old Mesa County Courthouse in Grand Junction to hear Thurlow “discuss his future plans for representing Mesa County in our Colorado State Legislature.”

Those plans were made clear in a candidate affidavit Thurlow filed Friday with the Colorado secretary of state’s office declaring his intentions to run for the Senate District 7 seat held by Scott, who is seeking a second term.

Asked recently by Colorado Politics whether he was considering running for the Senate seat in a primary – or as an unaffiliated candidate – Thurlow replied, “Don’t listen to rumors.”

It’s been no secret in Mesa County political circles Thurlow has been weighing a bid for Scott’s Senate seat – term-limited Mesa County Treasurer Janice Rich, a Republican, filed to run for Thurlow’s House seat last week but was coy when asked by the Grand Junction Daily Sentinel’s Charles Ashby to comment on mounting a primary challenge – but Colorado Politics is first to report that the moderate lawmaker held discussions last year with a national organization about running as an unaffiliated candidate.

Nick Troiano, executive director of the Denver-based Centrist Project – a group dedicated to electing independents that’s targeting a handful of Colorado legislative seats this election and has recently renamed its state-level operation Unite Colorado – told Colorado Politics Thurlow saw polling last year that showed Scott was vulnerable to an unaffiliated challenger.

“The Centrist Project approached Rep. Dan Thurlow a couple months ago to encourage him to consider running as an independent against Senator Ray Scott, who we believe exemplifies the problem of legislators in Denver who are beholden to partisan and special interests,” Troiano wrote in an email.

“We have had a series of subsequent conversations and meetings with Rep. Thurlow to discuss this opportunity, and we commissioned polling that demonstrated an independent candidate could defeat Senator Scott in a general election.”

Troiano declined to release details on the polling and said that he couldn’t confirm what Thurlow planned to do. But he added the group was “committed to doing all we can to recruit and support an independent candidate in SD-7, and we are in conversation with several other extraordinary community leaders about this possibility.”

To run as an unaffiliated candidate in this year’s election, Thurlow would have had to change his voter registration by Jan. 2, but state voter records – and the affidavit he filed for the Senate run – show he’s registered Republican.

By some measures, Thurlow is the most moderate House Republican. Last session, he split from the GOP caucus more often than any of his Republican colleagues on final, third-reading votes on bills, according to an analysis prepared by Colorado Capitol Watch.

Along with state Sen. Larry Crowder, R-Alamosa, Thurlow led the charge to revamp the formula used to set spending limits under TABOR – considered a third rail in state Republican politics – although the proposal didn’t pass. He also voted with the majority Democrats on a raft of topics, including an omnibus transportation bill that died in a Republican-controlled Senate committee and measures to ban gay conversion therapy and make it easier for transgender residents to change the sex on their birth certificates.

Thurlow’s votes across party lines spawned an aggressive Facebook page a few years back called “Recall Dan Thurlow” – its not-very-subtle original logo depicted an elephant attacking a rhinoceros, symbolizing a Republican in Name Only, or a “RINO” – although organizers told Colorado Politics plans to mount an actual recall fizzled.

Democrat Chris Kennedy, a Grand Junction city councilman who briefly ran for Congress last year, has filed to run for Thurlow’s Senate seat but told The Daily Sentinel last week that he plans to suss out the opposition before deciding whether to go ahead with a campaign – maintaining, as Ashby put it, “there’s a big difference between running against a far-right Republican such as Scott and a more moderate conservative such as Thurlow.”