Texas Republicans already concerned with holding onto the Senate seat being vacated by Sen. Phil Gramm are now faced with another challenge, a potential opponent who is a four-term House representative with considerable name recognition.

Rep. Ken Bentsen, D-Texas, nephew to former Texas senator and Clinton Treasury Secretary Lloyd Bentsen, announced Monday his intention to run for the seat.

If Bentsen were to win, it will be the first time a Democrat has taken the seat since 1961.  When Lyndon Johnson became vice president, the seat went to Republican John Tower and has stayed with Republicans since then.

"I want to be the Democrat who reclaims the seat of Lyndon Johnson, sits at the desk of Sam Houston and continues in the proud tradition of Lloyd Bentsen," he said. "I want to put my experience and record of accomplishment to work for all the people of Texas in the United States Senate," Bentsen said in McAllen, Texas.

Bentsen, 42, has fought off some rough challenges before.  Painted as a liberal by Republicans, Bentsen campaigned as a moderate, favoring a balanced budget, welfare reform, abortion rights and environmental protection.

A senior member of the House Budget Committee and Financial Services Committee, he has also touted his record for pushing paying down the national debt and funneling federal money for education, law enforcement, health care and medical research.

A three-term senator, Gramm announced earlier this year that he was leaving office. 

Bentsen, a former investment banker and congressional aide, will first have to mount the hurdle of a primary in March, in which he will face several Democrats. Two Republicans are seeking their party's nomination.

Had he pursued his House seat again, redistricting would likely have forced him to race against another Democrat incumbent, Sheila Jackson Lee.

The Associated Press contributed to this report.