Biden son won't run for US Senate

US Vice President Joe Biden's son, Beau Biden, announced Monday that he would not run to fill the Senate seat previously held by his father, feeding Democratic election-year worries.

"I cannot and will not run for the United States Senate in 2010," the younger Biden said, adding that he would instead run for reelection as attorney general in his home state of Delaware.

President Barack Obama's Democrats fear the November mid-term elections -- a contest that typically sees the party that holds the White House lose seats in the Congress -- could cost them dearly.

Beau Biden had widely been expected to run for the seat his father held for 36 years and left to serve as Obama's vice president, but recent polls showed he faced a tough opponent in Republican Representative Mike Castle.

Long-time Biden aide Ted Kaufman is currently serving out the rest of Joe Biden's term but has repeatedly said he has no interest in running.

The decision came as Democrats still reeled from the shock Republican victory in a special election in Massachusetts to fill the seat held by the late Democratic icon Ted Kennedy.

In his statement, Beau Biden made no reference to Democrats' sour political prospects and said he was staying on to prosecute a horrific child abuse case in which an pediatrician has been charged with raping nine patients and may have molested up to 100.

"Justice can be done. And I am determined to see that it is. I have a job to finish. And that?s what I must do," said the Delaware attorney general.