On the same day a new poll showed Colorado’s U.S. Senate race between Democrat Mark Udall and Republican Cory Gardner virtually tied, a new candidate entered the race, saying neither party was capable of ending partisan bickering long enough to fix Washington.

Neurosurgeon Steve Shogan is a former Democrat who has been an unaffiliated voter since 2007.

“Congress is stuck in a hopeless logjam. Nothing will ever change in Washington until the political landscape changes,” he said. “I would ask, ‘What could possibly be more of a wasted vote than to continue to put the same failing parties back into office?’ ”

Shogan has a long history of community service with influential Colorado groups, and his entry into the race has the potential to be a spoiler considering the two leading candidates are neck and neck.

Sen. Udall is leading Congressman Gardner 45 percent to 44 percent, but the senator’s approval ratings have dropped and fewer voters think he should be re-elected, a Quinnipiac University poll released Thursday shows.

“I’m doing this not to be a spoiler but to win and change things in Washington,” Shogan said.

He kicked off his campaign at a hotel room in Glendale filled with family and friends, including medical staffers who dashed over in their hospital scrubs during their lunch hour.

Shogan later drove around the metro area in an ambulance he rented and covered with campaign signs to promote his candidacy.

“I think it’s supposed to be symbolic of the fact that this country really in some ways requires emergency care. There are a number of problems we need to cure,” he said.

The partisan stalemate in Washington has led to sequesters, government shutdowns and the downgrading of America’s credit, he said.

Asked by Quinnipiac the most important issue in deciding their U.S. Senate vote, Colorado voters listed the economy or jobs, 16 percent, and health care, 14 percent.

“No other issue comes close,” Quinnipiac reported.

The poll shows Udall leading 52 percent to 35 percent among women — the same audience he targeted when he released his first campaign ad this week. The spot blisters Gardner’s position on abortion and birth control. Gardner leads 53 percent to 38 percent among men.

Colorado voters oppose the Affordable Care Act 59 percent to 37 percent, the poll found. Udall voted for the measure and has been hit with two ads — one unveiled Wednesday after the poll was conducted — from the conservative group Americans for Prosperity over his support for Obamacare.

Shogan believes Obamacare is a “fatally flawed program that won’t accomplish its aims, will kill jobs and will add trillions to our debt.”

Since 1984, he has served as chief of neurosurgery at Rose Medical Center and as an assistant clinical professor at the University of Colorado Health Sciences Center, although he is putting his medical career on hold during the campaign.

“I’m a product of the ’60s, and we really believed we were going to make a much better world of things. Unfortunately, we have not fulfilled on our promise to do that,” Shogan said. “Even though I’ve really gotten a lot of satisfaction out of being a physician, I would like to do something in a bigger way. I know that sounds kind of hokey, but that actually is the truth.”

Lynn Bartels: 303-954-5327, lbartels@denverpost.com or twitter.com/lynn_bartels