Republicans have a real shot at knocking off Colorado Gov. John Hickenlooper (D) in 2014, according to a Quinnipiac University poll released Thursday showing the incumbent running neck-and-neck with former congressman Tom Tancredo (R).

Hickenlooper leads Tancredo 42 percent to 41 percent, well within the survey's margin of error. Colorado voters are now split over the once widely popular governor, with 47 percent approving of the job he is doing and 43 percent disapproving.

One explanation for Hickenlooper's plight is his decision to grant Nathan Dunlap a temporary reprieve that likely means Dunlap won't face execution so long as Hickenlooper is governor. Dunlap was convicted of killing four people in 1993.

By an overwhelming margin, voters disagree with the governor's decision. Nearly seven in 10 (67 percent) disapprove of it while only about three in 10 (27 percent) approve.

"By nearly 3-1, Colorado voters support the death penalty in their state and say where their elected officials stand on it could affect their vote," said Quinnipiac pollster Tim Malloy.

Tancredo recently announced his intention to challenge Hickenlooper, saying in an interview that “this Dunlap thing is the last straw." Tancredo ran for governor as a third-party candidate in 2010 on the American Constitution Party ticket. He finished well ahead of Republican nominee Dan Maes but lost to Hickenlooper by 15 points. Tancredo has since rejoined the GOP.

Tested against two other possible Republican candidates, Secretary of State Scott Gessler and state Sen. Greg Brophy, Hickenlooper also faces close races.