DENVER—Former U.S. Rep. Tom Tancredo has become the latest Republican to announce plans to challenge Democratic Gov. John Hickenlooper.

Tancredo said Thursday on radio station KHOW the last straw was a decision by Hickenlooper to delay the execution of convicted murderer of Nathan Dunlap, who killed four people in 1993. Tancredo said he is also upset with Hickenlooper’s approval of sweeping gun legislation this year, including a law limiting the size of ammunition magazines.

“I’m going to run for governor for the state of Colorado, and I’m going to do it this time as a Republican,” Tancredo said Thursday.

Hickenlooper cruised to victory in 2010 after the Republican side of the ticket imploded. Tea party favorite Dan Maes won the party nomination when a better-funded candidate, former U.S. Rep. Scott McInnis, was accused of plagiarism. Tancredo then declared Maes unelectable and briefly left the party to run as a third-party candidate.

Steve Laffey, a onetime Republican U.S. Senate candidate in Rhode Island, announced Tuesday he’s also running for governor of Colorado.

Republican Secretary of State Scott Gessler has said he will decide next week whether to run.

Tancredo gained national attention for blistering attacks on illegal immigrants and briefly ran for president in 2008.

He continued his attacks on the Republican Party on Thursday, saying it would rather run a middle-of-the-road candidate in hopes the person won’t offend enough people to lose the race.

“I think it’s absolutely the wrong position to take. You should be looking for people who are committed to principle,” Tancredo said.

“They’re hoping they get some guy who’s very, very wealthy, can fund his own campaign, can skirt the issues and run down the middle. But it doesn’t work that way.”

State GOP chairman Ryan Call defended the party, saying it has a number of good candidates, each bringing their own strengths.

“It will be up to the Republican voters to decide who represents our party,” Call said.