By Ebong Udoma
NEW BRITAIN, Connecticut (Reuters) - Connecticut Democrats on Saturday backed Congressman Christopher Murphy to be the party's nominee for an open U.S. Senate seat in November's election, but the vote margin was not enough for him to avoid a primary contest in August.
Murphy got 76 percent of the votes at the state party convention to pick the party's nominee for the Senate seat long held by Joseph Lieberman, a Democrat turned independent who announced last year he would not seek re-election.
Murphy defeated former Connecticut Secretary of the State Susan Bysiewicz, who garnered 24 percent of the delegates, enough to force Murphy into a party primary in August.
Lieberman held the seat for 24 years, first as a Democrat and the last six years as an independent. He was the Democratic vice-presidential nominee in 2000.
"The overwhelming endorsement of this convention gives me faith that we will win this race," a beaming Murphy told delegates after the vote.
If he wins the primary, the 39-year-old three-term congressman will face a Republican from a field that includes former Connecticut Congressman Christopher Shays and former professional wrestling executive Linda McMahon, who spent $50 million of her own money in an unsuccessful run for the U.S. Senate two years ago.
The Republican party convention is on May 18.
Connecticut is traditionally a Democrat-leaning state and the seat is rated by the Cook Political Report as likely to be won by a Democrat. But McMahon's willingness to spend her own money and Shays' moderate Republican record in Congress give Republicans hope in the race as they struggle to wrest control of the Senate from Democrats.
A former state representative and state senator, Murphy's first job in politics was as an intern to former U.S. Senator Chris Dodd.
In 1996, he was campaign manager for Charlotte Koskoff, who nearly upset Republican Congresswoman Nancy Johnson. A decade later Murphy himself defeated Johnson.
Lieberman, former vice president Al Gore's running mate in the disputed election of 2000 awarded to Republican George W. Bush, announced his retirement from the Senate last year.
After a long political career as a Democrat, Lieberman angered Connecticut Democrats with his support for the Iraq war in 2003. He ran for re-election as an independent in 2006 and won a fourth term in the Senate.
(Editing by Greg McCune and Vicki Allen)