A poll conducted for liberal campaign finance reform group End Citizens United found Democrat Jason Crow leading U.S. Rep. Mike Coffman, an Aurora Republican, by 5 points – and the challenger’s advantage increases to 10 points after poll respondents were told Crow isn’t taking corporate PAC money.

The Democratic-leaning Public Policy Polling survey shows Crow, one of four Democrats running in Colorado’s 6th Congressional District, ahead of Coffman 44-39 percent, with 16 percent undecided.

According to the survey of 6th District voters, 62 percent said they were more likely to support a candidate who won’t accept contributions from “corporate special interests” – a pledge Crow made last fall when he won End Citizens United’s endorsement.

After pollsters told respondents Crow “is not taking a dime” from corporate PACs  and that Coffman “has accepted $1.6 million from corporate PACs and just voted to give corporations a huge tax cut,” Crow’s lead grows to 48-38 percent.

“Voters are fed up with the way Washington does business and they’re demanding reform,” Tiffany Muller, president of End Citizens United,  said in a statement. “It’s no surprise that Coloradans are rallying behind Jason Crow and his commitment to reject corporate PAC money.” She added that Coffman’s history of taking special-interest contributions “will come back to haunt him on Election Day.”

Coffman’s campaign manger, Tyler Sandberg, dismissed the survey results.

“To quote Mark Twain, reports of Mike Coffman’s demise are greatly exaggerated,” Sandberg told Colorado Politics. “This is the same old tired playbook national Democrats have used the last three election cycles – and Mike Coffman’s margin of victory has only grown each time.”

A PPP poll conducted in early October 2013 showed Coffman losing by 8 points to a generic Democrat – and by 10 points after Coffman’s vote in favor of the recent government shutdown was brought to respondents’ attention – but he went on to prevail over Democratic challenger Morgan Carroll by just over 8 points a year later.

In December, Coffman landed on a list of lawmakers targeted by End Citizens United. The PAC said it intends to spend $35 million this cycle to defeat “incumbents who do the bidding of special interests while also voting to keep the rigged system in place.” In Coffman’s case, the group pointed to more than $100,000 Coffman has taken from gun-rights organizations, a point Crow made in a digital ad released last week.

The survey also showed that President Donald Trump has a fordable rating with 39 percent of respondents and was viewed unfavorably by 57 percent.

The survey was conducted using automated telephone interviews Feb. 15-18 and has a margin of error of plus-or-minus 3.6 percent, the pollsters said.

Three other Democrats – Levi Tillemann, David Aarestad and Erik Stanger, all of Aurora – are running for the chance to take on Coffman, and Coffman is facing a primary challenge from Highlands Ranch Republican Roger Edwards. The survey didn’t measure any of their chances against Coffman.