03/28/2012 01:28 pm ET

Don Bivens Drops Out Of 2012 Arizona Senate Race, Clearing The Way For Richard Carmona

WASHINGTON -- Don Bivens, a top Democratic challenger in Arizona's U.S. Senate race, announced Wednesday that he was ending his campaign because a competitive primary battle was draining resources the party needed to win in November.

Bivens' withdrawal clears a path in the Democratic primary for former Surgeon General Richard Carmona. While Bivens, a former state party chairman entered the race first, Democratic officials in Washington made clear they believed that Carmona stood the best chance of winning a general election.

"While I am confident we would win this primary, the cost and impact on the party I've spent my life fighting for could diminish our chance to achieve the ultimate goal -- winning in November," Bivens said in a written statement.

Democratic leaders in Washington praised Bivens, but they did him few favors by advocating so aggressively for Carmona.

"Don Bivens has had a diverse and distinguished career in business, law and public service," said Sen. Patty Murray, chairman of the Democratic Senatorial Campaign Committee. "His leadership in our party has been critical to our success in Arizona. I know that Don will continue to contribute to our party and our country in the months and years to come."

Carmona released this statement:

Don Bivens is a cornerstone of the Arizona Democratic Party and will remain so for years to come. An agent of change for our state, Don knew how great of an opportunity we have to win this seat and knew that it would take a strong and united effort to do so. He and his team ran a strong race that showed a great deal of respect for the nominating process which in turn has improved our party's chance of success in November.

I thank Don, his family and his campaign team for their selfless service to the party and eagerly anticipate working with them to move Arizona forward. He will be an integral player in any winning strategy and I look forward to working with him in the months ahead.

Democrats have targeted Arizona as an opportunity to win a seat now held by retiring Republican Sen. Jon Kyl.

Rep. Jeff Flake and businessman Wil Cardon are competing in Arizona's Republican primary. Flake is viewed as the heavy favorite.