BOCA RATON, Fla. -- State Sen. Ron Klein, a former Senate Democratic leader, announced Thursday he would challenge Republican U.S. Rep. Clay Shaw in the November 2006 election.

Klein, a state lawmaker since 1992, has helped lead efforts to lower homeowner's insurance, prescription drug costs and to bring the Scripps Research Institute to Palm Beach County.

Klein said he would focus on health care, education and fight against any plan that undermines Social Security.

"Social Security must be protected and strengthened within the confines of a fiscally responsible budget - not weakened with a scheme that will increase our nation's debt by trillions of dollars," he said in a statement.

Klein will be trying to unseat Shaw, of Fort Lauderdale, who has held the seat since 1981.

Shaw easily won re-election last November, defeating Hollywood Democrat Robin Rorapaugh with 62 percent of the vote. She was a replacement chosen by party officials for Jim Stork, whose name was still on ballots although he withdrew. Klein considered running in Stork's place last year but decided against it.

Klein, 49, served as a state representative from 1992 to 1996 before being elected to the state Senate. He lives in Boca Raton with his wife, Dori, and two children.