WASHINGTON -- Senator Lincoln Chafee's office said yesterday that his constituency is ''overwhelmingly" opposed to the nomination of John Bolton as US ambassador to the United Nations, signaling that Chafee is leaning against supporting Bolton in a move that could derail the nomination.
If Chafee, a moderate Republican from Rhode Island who serves on the Senate Foreign Relations Committee, joins with Democrats who are expected to unanimously oppose the nomination, Republicans will not have enough votes to send the confirmation to the Senate floor.
Bolton, one of President Bush's most controversial nominees, has strongly criticized and at times ridiculed the United Nations. His nomination comes at a time when the Bush administration has signaled its intention to play a leading role in overhauling the UN.
He will testify before the Foreign Relations committee tomorrow. Several senators, including Chafee, have said the testimony will be important in their decisions whether to support him.
But as the hearing approaches, the nomination is becoming a bitter political battle, increasingly centering on Chafee. Groups that oppose Bolton have launched television and radio ads in Rhode Island, a liberal state that voted against Bush for president by a large margin.
In recent days, Chafee's Washington office has received about 500 calls and e-mails about Bolton's nomination, and fewer than 10 of them supported Bolton, said Stephen Hourahan, the senator's press secretary.
''We are overwhelmingly hearing from the people of Rhode Island that they are opposed to the Bolton nomination," said Hourahan, who said that Chafee is still undecided about Bolton. But he said that, in the past, Chafee ''has voted mostly with the people of Rhode Island's interests in mind."
Hourahan said Chafee had just returned from Rhode Island and was unavailable for comment.
Yesterday, Julie Reside, a State Department spokesman, said, ''Mr. Bolton is an excellent nominee and we certainly hope he will be confirmed quickly."
Bolton and Secretary of State Condoleezza Rice met with Chafee within 24 hours of Bolton's nomination, seeking the senator's backing.
During the meeting, Rice and Bolton addressed many of Chafee's concerns, which centered on modifying Bolton's sometimes caustic approach to diplomacy and ensuring that the United Nations will continue to play a serious role in American foreign policy.
After the meeting, Chafee's spokesman indicated that the senator was ''inclined to support" Bolton's nomination. But in the weeks that followed, Bolton's critics have launched an intense campaign against him, focusing much of their efforts on Rhode Island, where Chafee is up for reelection next year.
Citizens for Global Solutions, a national grass-roots group that advocates for international institutions, including the United Nations, has spent about $20,000 in Rhode Island to air a television ad against Bolton on Fox News, NBC, CBS, and two radio stations, according to Harpinder Athwal, communications director for the group.
The group also launched a website, www.stopbolton.org, which encourages viewers to sign a petition and write letters to senators in key states, including Chafee.
Hourahan said that 110 people contacted Chafee's Washington office on Monday alone, most of whom said they had received an e-mail from the office of Senator John F. Kerry, Democrat of Massachusetts, about the Bolton nomination.
Debbie Rich, a Chafee spokesman in Providence, said that fewer calls had come into the Providence office, but that ''most of the calls that are coming in are about Bolton, and the majority of the calls that are coming in are against his nomination."
Hourahan estimated that in Rhode Island 40 percent of voters are registered Democrats, 50 percent are independent, and 10 percent are Republicans. Over the years, Chafee has often gone against the grain of his party.
He was the only Republican to vote against the White House war resolution in October 2002 leading up to the invasion of Iraq, and was one of two Republicans to vote against Bush's tax cuts.
''We have been in this position many times, and the leaders [of the party] understand where he is coming from, as far as the role that he plays in the party," Hourahan said. ''It's pressure, but it is also something that we have been accustomed to."
In his reelection bid next year, Chafee could face formidable opposition from Secretary of State Matthew A. Brown, a Democrat, who has already begun raising money for the campaign. As a moderate, he could also face a conservative challenger from the Republican party.
Bolton faced near unanimous opposition from Democrats four years ago when he was nominated for his current post as undersecretary for arms control. Only one Democrat, Russell Feingold of Wisconsin, voted for him, citing the need to support a new president's nominees.
But Feingold now is undecided about whether or not to support Bolton, and Democratic staff members in the Senate said they expected all eight Democrats on the committee to vote against Bolton.
If just one of the 10 Republicans on the committee joins them, the 9-to-9 tie would prevent the nomination from moving to the Senate floor.
Republican members of the committee would then offer a second resolution referring the matter to the Senate without a positive recommendation. That resolution would also require a majority, which could once again hinge on Chafee.
Committee aides said the Republican-controlled Senate would probably confirm Bolton if the nomination made it out of the committee.