Republican lead narrows in Colorado race: Reuters/Ipsos poll

Republican Senate candidate Ken Buck gives his acceptance speech to supporters at an election night party in Loveland, Colorado after he defeated Jane Norton in the Republican primary election August 10, 2010.

WASHINGTON (Reuters) - Republican Ken Buck has a dwindling lead over Democratic incumbent Michael Bennet, who has gained ground in Colorado's U.S. Senate race since August, according to a Reuters/Ipsos poll released on Tuesday.

Buck, a favorite of the conservative Tea Party movement, leads Bennet among likely voters by 48 percent to 45 percent. Buck led by 9 percentage points in August shortly after winning the Republican Senate nomination in a bitter primary fight.

More than half of Colorado voters say the struggling economy is the top issue and the state is on the wrong track, but Buck, a former prosecutor, has been unable to make political headway despite the sour voter mood.

"This race is narrowing pretty substantially," Ipsos pollster Julia Clark said, noting Buck's support had remained essentially frozen since August, while Bennet had improved by five percentage points.

"Bennet seems to have some momentum," she said. "A Tea Party candidate like Buck should be doing better in this political environment."

Public discontent with President Barack Obama and the ailing economy has swept Republicans into position to gain control of the House of Representatives and perhaps even pick up the 10 Democratic seats they need for a Senate majority.

The contest in Colorado is a key Senate race that could decide the balance of power. Republicans probably need wins in seven of eight toss-up Senate races in Democratic-held states, including Colorado, to take control of the Senate and hand Obama a disastrous defeat.

Obama has visited Colorado to support Bennet, a former Denver schools chief who was not widely known before he was appointed last year to replace Ken Salazar, who became Interior Secretary.

Buck has criticized Bennet as a rubber-stamp for Obama's legislative agenda and condemned his votes for the healthcare overhaul, economic stimulus and auto industry bailouts.

But voters backed Bennet's approach on healthcare over Buck by 43 percent to 36 percent, the poll found, and supported Bennet on the issue of abortion rights by 50 percent to 27 percent.

Bennet has attacked Buck's refusal to prosecute a 2005 rape case as a district attorney. Buck, who later told a newspaper the jury might have felt the accusations were a case of "buyer's remorse" by the victim, has said the case was weak.

SMALL BUCK LEAD ON TAXES

With the help of Tea Party activists who favor lower taxes and lower federal spending, Buck beat the Republican establishment candidate in a bitter primary fight in August.

The Tea Party, which gets its name from the 1773 Boston Tea Party anti-tax protest in which Bostonians tossed crates of tea into the city's harbor to denounce a British tea tax, is a loosely organized movement harshly critical of Obama.

The poll found voters preferred Buck's approach on taxes over Bennet by 41 percent to 38 percent, within the margin of error.

"It's interesting that they are so close on taxes. A real Tea Party candidate should do better on that issue," Clark said.

About six in 10 voters in the poll said they identified with the Tea Party to some degree, with 36 percent saying they did not identify with them at all. About two-thirds of voters said Buck was aligned with the Tea Party.

In the race for governor, Democrat John Hickenlooper leads third-party candidate Tom Tancredo, a former Republican congressman, by 46 percent to 35 percent. Republican Dan Maes trails badly with 14 percent of likely voters.

The poll was largely taken before Buck and Bennet squared off in a debate on Sunday NBC's "Meet the Press" program. During the encounter Buck, pressed on whether homosexuality was a lifestyle choice, said "birth has an influence over it, like alcoholism and some other things."

As in other polls, Republicans were more enthusiastic about voting in two weeks than Democrats, with 72 percent saying they are certain to vote, versus 55 percent of Democrats.

The Ipsos poll of 600 registered voters, including 405 who said they were likely to vote, was taken from Friday through Sunday.

The full survey of registered voters has a margin of error of 4 percentage points, while the smaller sample of likely voters has a margin of error of 4.9 percentage points.

(Editing by Paul Simao)