Susan Page

USA TODAY

In Colorado, the state where Barack Obama was first nominated for the White House, he has emerged as a drag on the re-election prospects of Democratic Sen. Mark Udall and Gov. John Hickenlooper, a USA TODAY/Suffolk University Poll finds.

The survey shows Udall at 42%, Republican challenger Cory Gardner at 43% in what is essentially a tie. The poll of 500 likely voters, taken Saturday through Tuesday, has a margin of error of plus or minus 4.4 percentage points.

The governor's race also is too close to call: Hickenlooper is at 43%, Republican challenger Bob Beauprez at 41%.

The 2008 Democratic convention that nominated Obama was held in Denver, and the Centennial State twice has cast its electoral votes for him. But those surveyed now disapprove of the job he's doing as president by 56%-42%. His favorable-unfavorable rating also is upside down, with a 55% majority saying they have an unfavorable view of him, 43% a favorable one.

Those ratings are worse than those for Udall or for Hickenlooper. By 2-1, 37%-19%, those surveyed say they think of their vote for Congress as a vote against Obama, not for him.

What's more, by 55%-37% they say the Affordable Care Act, the signature health care law Obama signed in 2010, generally has been bad for Colorado.

"I don't like any of the Congress or the president," Mark Richardson of Englewood, Colo., who was among those polled, said in a follow-up interview. "I don't think they've done anything for us for the last 10 or 12 years, just bickering among themselves." The general contractor, 50, supports Congressman Gardner.

But Diana Nitz, 64, a retiree in Glenwood Springs, says she gives Obama "a lot of credit for good leadership," adding: "He plays a nice chess game and I think he's got a strategy that isn't as obvious to most people." Gardner is "very extreme," the Udall supporter says. "He's got a lot of energy but it's going in the wrong direction."

Hickenlooper is locked in a tight race even though he has a net favorable rating, 46%-42%, and half of those surveyed say the state's economy has improved in the past two years. Another three in 10 say it's stayed the same. Beauprez's favorable-unfavorable rating is 36%-34%.

One in 10 voters remain undecided.

When it comes to House races, those surveyed say by 46%-40% that they plan to vote for the Republican candidate, not the Democratic one.

The nation's polarized political state is a factor in those votes. Two-thirds say the issue of which party controls Congress is a factor in their decision. Those voters split almost evenly between the two parties in the Senate and House races.

"The polling tell us that Democrats are being slowed down by the headwinds of President Obama and Obamacare at the moment," says David Paleologos, director of the Political Research Center at Suffolk University, in Boston. "But winds can shift or subside so it's a matter of what the political weather conditions are on Election Day."

This summer, Hickenlooper hosted Obama for beer and a game of pool in Denver. But Udall has sought to keep his distance from the president and some of his policies. "Let me tell you, the White House when they look down the front lawn, the last person they want to see coming is me," Udall said last week at the first Senate campaign debate against Gardner.

Meanwhile, in the 2016 presidential contest:

• The GOP field remains diffuse, with 16% of Colorado Republicans undecided about whom to support. Only Kentucky Sen. Rand Paul and Wisconsin Rep. Paul Ryan break into double digits, at 12% and 10%. They're followed at 8% by New Jersey Gov. Chris Christie, former Arkansas governor Mike Huckabee and Wisconsin Gov. Scott Walker.

If 2012 nominee Mitt Romney jumped in the race, he would take an instant lead at 35%.

• The Democratic field is dominated by former secretary of State Hillary Rodham Clinton, supported by 59%. But Massachusetts Sen. Elizabeth Warren, a populist champion who says she doesn't plan to run, is backed by 21%. That's well ahead of Vice President Biden, who has made it clear he would like to run, at 8%.

The Colorado Senate contest has featured Republican ads that tie Udall to Obama and Democratic ads that portray Gardner as a threat to women on issues such as contraception. The negative back-and-forth is apparent when the poll asked respondents what came to mind when they heard the candidates' names.

For Udall, the most frequent specific responses were "Obama follower/puppet," "liberal" and "dishonest/untrustworthy." His job-approval rating is 42% approve, 49% disapprove. His favorable-unfavorable rating is 43%-44%.

For Gardner, the most frequent specific responses were "pro-life/anti-abortion," "honest" and "liar." His favorable-unfavorable rating is 41%-37%.

Geographically, Udall scores a 22-point lead in the Denver/Boulder area, but he's tied or losing elsewhere in the state. In the eastern part, which overlaps Gardner's congressional district, the Republican is ahead by 18 points.

The survey shows more likely voters identify themselves as Republicans than Democrats, 33% to 31%. "Those extra 60,000 registered Republicans could factor in the outcome," Paleologos says, noting there also are indications Republicans are more enthusiastic about voting this year. "Democratic candidates in Colorado need to offset the possibility that the midterm cycle might mean lower turnout among young and minority voters who should be mailing it in."

Two other statewide polls this month, by the Denver Post/Survey USA and NBC News/Marist, showed Udall in a slightly stronger position overall, with leads of 4 and 6 percentage points. The other surveys showed Hickenlooper with similar narrow leads, of 2 and 4 points, although a Quinnipiac Poll released Wednesday showed Beauprez with a 10-point lead.