Sen. Mark UdallMark Emery UdallSenate GOP rejects Trump’s call to go big on gun legislation Democratic primary could upend bid for Colorado seat Picking 2018 candidates pits McConnell vs. GOP groups MORE (D-Colo.) is locked in a statistical tie with Rep. Cory GardnerCory Scott GardnerSessions floats federal law that would protect states that decriminalize marijuana RNC mum on whether it will support Trump-backed Corey Stewart Overnight Health Care — Sponsored by PCMA — Dems see midterm advantage in new ObamaCare fight MORE (R) in a new poll of the Colorado Senate race

The Quinnipiac University survey gives Udall 45 percent support to Gardner’s 44 percent support among registered Colorado voters, within the poll's 2.7-point margin of error.

It’s the second poll in as many days that shows Udall facing a difficult reelection fight this fall. A survey conducted by a Republican-leaning pollster commissioned by the Chamber of Commerce out Wednesday showed Gardner leading Udall by two points, 44 percent-42 percent.

In the Quinnipiac survey, Udall has a 17-point lead among female voters, while Gardner has a similar lead among men. The senator is looking to exploit that gender gap in the race and has made Gardner’s record on women’s issues, and particularly his support for measures that would give a fertilized human egg legal rights, a central focus of his attacks on the candidate.

Both candidates have strong support from their respective bases, but Gardner takes a slight lead with independents, 43 percent to Udall’s 41 percent.

Perhaps most troubling for Udall in the new Quinnipiac Poll is the fact that voters are split, 42 percent evenly, on whether they think he’s doing a good job — and a slight plurality, 46 percent, say he doesn’t deserve to be reelected.

Gardner leads by double digits among voters who list the economy and healthcare as their main concerns this November — overall, about a third of the electorate.

Driving dissatisfaction with the Democrat is the fact ObamaCare’s numbers are dismal in the state, with just 37 percent approving of the law, while 59 percent disapprove, figures that echo those from the Chamber of Commerce’s poll. President Obama’s approval rating is near-identical to ObamaCare’s approval in the state.

It’s those numbers that have given Republicans high hopes for Colorado and encouraged Gardner to jump in the race earlier this year, giving the GOP a top-tier contender and a shot at the typically blue-leaning seat.

The poll was conducted among 1,298 registered voters from April 15-21 via land line and cellphones.

— This piece was corrected at 9:30 a.m. to reflect the fact that Gardner leads Udall in the Chamber of Commerce poll.