08/10/2010 10:19 pm ET | Updated May 25, 2011

Michael Bennet Wins Colorado Democratic Senate Primary

Andrew Romanoff, challenger for the Democratic Senate nomination in Colorado, has conceded to his opponent, Michael Bennet.

Bennet, an appointed incumbent facing the first election of his career, held a commanding 54-45 lead with 67% of precincts reporting on Tuesday night.

The victory for Bennet caps a long and heated primary during which Romanoff, a former Speaker of the Colorado State House, closed a significant gap in the polls by portraying himself as an outsider running against Washington special interests.

Romanoff, who did not take money from PAC's, was vastly outspent by Bennet, but managed to pull ahead in some polls on the strength of his anti-Washington message, as well as some pointed attack ads aimed at Bennet's ties to Wall Street.

Bennet, a former superintendent of the Denver Public School system also had the strong backing of the White House. Romanoff was endorsed by former President Bill Clinton.

Obama called to congratulate Bennet shortly after Romanoff's concession

In his victory speech, Bennet gave a nod to Romanoff, whose supporters he will need to win over in order to win reelection in November. "Andrew has spent his career committed to this state and to our party," Bennet said. "I look forward to working with him."

DNC Chairman Tim Kaine will be in Colorado this week to take part in a Democratic party unity event.

Romanoff has pledged his support to Bennet's general election campaign.

Bennet will face Ken Buck in what is expected to be a hard-fought general election in Colorado.

In a statement Tuesday night, John Cornyn, Chairman of the National Republican Senatorial Committee wasted no time in attempting to portray Bennet as a partisan Democrat.

"Despite trying to cast himself as a political 'outsider,' Senator Bennet eagerly toed the party line," Cornyn said.

He also pointed to an article in The Hill, which made the case that Bennet faces "an uphill battle" in the general election due to his low approval rating.