Washington ? President Bush’s choice to be U.S. ambassador to the United Nations should withdraw from consideration or risk embarrassing the president, a Senate Democrat said Sunday. The White House said it stood by John Bolton.

A Republican colleague said “it’s too close to call” as to whether the Senate will confirm Bolton, who awaits a vote by the Senate Foreign Relations Committee on May 12.

“I think the best policy is to have his nomination come to the full Senate, not decided by a committee because the Constitution says that advice and consent are the province of the Senate itself,” said Sen. Arlen Specter, R-Pa., on CNN’s “Late Edition.”

One committee member, Sen. Christopher Dodd, D-Conn., was asked whether he thought Bolton should withdraw from consideration. “I would hope he would,” Dodd told CBS’ “Face the Nation.”

“I think he’s going to embarrass the president. I think he’s going to … have a very difficult job serving if he’s confirmed narrowly by the Senate. He should withdraw or the president ought to withdraw this nomination. There are plenty of other good people who embrace his ideological views who can go up” and achieve the major changes that Bush is pressing for at the United Nations. “John Bolton is not that individual.”

Bolton has come under fire over allegations he dressed down subordinates or behaved, as one former colleague claimed, “like a madman,” when he was crossed. In addition, there is unease over Bolton’s past hostility toward the United Nations and accusations that he tried to pressure career intelligence analysts into twisting facts for political reasons.

Sen. Dick Durbin of Illinois, the second-ranking Democrat, told “Fox News Sunday” that he thought Bolton’s nomination was “in trouble.”

Defenders said Bolton, now the undersecretary of state for arms control and international security, has a tough-talking style that will help achieve needed reforms at the United Nations.

“Look, we’re not nominating somebody here for Miss Congeniality,” said Sen. Mitch McConnell, R-Ky. “We know that Bolton is a person, a forceful person, a person of strong opinion.”