The White House cannot count on much backing from Democrats to confirm John R. Bolton, as Republicans seek to shore up support for the ambassador to the United Nations nominee before a Senate floor vote later this month.
Meanwhile, though, Republicans appear to be rallying behind Mr. Bolton, with key senators such as Susan Collins of Maine and Mike DeWine of Ohio saying they plan to support him when the Senate takes up his nomination, probably next week.
“I’m giving deference to the president’s choice for the United Nations,” Mr. DeWine said, while Miss Collins said Mr. Bolton would not have been her choice, but “I think he’s qualified for the position.”
Most Democrats voted against Mr. Bolton in 2001, when he was confirmed to be under secretary of state for arms control and international security. Of those who either voted for him or weren’t in the Senate at the time, most either have announced they now oppose him or are leaning against him.
“Some of these new revelations are troubling, very troubling,” said Sen. Mary L. Landrieu, Louisiana Democrat, who was one of seven Democrats to vote for Mr. Bolton when he was confirmed 57-43 in 2001.
Still, with Republicans holding a majority, that means only a Democratic filibuster could stop him — a decision that has not yet been made.
“My general feeling is that we shouldn’t rule it out,” said Sen. Christopher J. Dodd, Connecticut Democrat, who has been among the harshest critics of President Bush’s nominee, accusing him of bullying subordinates and pressuring intelligence agents in the State Department.
Mr. Bolton’s nomination was sent from the Senate Foreign Relations Committee to the full Senate without a positive recommendation. Sen. George V. Voinovich, Ohio Republican, said he cannot support the nomination but did not want to block a floor vote.
So far, he is the only Republican who has committed to opposing Mr. Bolton in that floor vote.
Of the seven Democrats who voted for Mr. Bolton in 2001, two are no longer in the Senate. Of the others, Mrs. Landrieu, Sen. Ben Nelson of Nebraska and Sen. Joe Lieberman of Connecticut have not decided how they will vote, the senators or their aides said. The other two, Sen. Russell D. Feingold of Wisconsin and Sen. Evan Bayh of Indiana, will oppose him based on his performance as under secretary during the past four years.
There are also four Democrats who were not in the Senate in 2001 and who will have to vote on Mr. Bolton for the first time. As of now, Mr. Bolton can’t count on support from any of them.
“I have very grave reservations about him, but I haven’t made a final decision,” said Sen. Ken Salazar of Colorado.
Sen. Frank R. Lautenberg of New Jersey said he is leaning against voting for Mr. Bolton. Sen. Barack Obama of Illinois already voted against Mr. Bolton in committee.
And Sen. Mark Pryor of Arkansas has not decided how he will vote, his spokesman said.