Mr. Dole last March. A majority of his fellow Republicans voted against the treaty, citing concerns about sovereignty.
Senators from both parties went to greet Mr. Dole, leaning in to hear his wispy reply, as he sat in support of the treaty, which would require that people with disabilities have the same general rights as those without disabilities. Several members took the unusual step of voting aye while seated at their desks, out of respect for Mr. Dole, 89, a Republican who was the majority leader.
Then, after Mr. Dole’s wife, Elizabeth, rolled him off the floor, Republicans quietly voted down the treaty that the ailing Mr. Dole, recently released from Walter Reed National Military Medical Center, so longed to see passed.
A majority of Republicans who voted against the treaty, which was modeled on the Americans With Disabilities Act, said they feared that it would infringe on American sovereignty.
Among their fears about the disabilities convention were that it would codify standards enumerated in the United Nations Convention on the Rights of the Child — and therefore United Nations bureaucrats would be empowered to make decisions about the needs of disabled children — and that it could trump state laws concerning people with disabilities. Proponents of the bill said these concerns were unfounded.
The measure, which required two-thirds support for approval, failed on a vote of 61 to 38.
Mr. Kerry, Democrat of Massachusetts, his voice rising as senator after senator moved slowly into the chamber, rejected the concerns of Republicans and made a moral argument for approval of the treaty.
Mr. Dole, he said, had not come to the Senate floor “to advocate for the United Nations.”
“He is here because he wants to know that other countries will come to treat the disabled as we do,” he added.
Approval of the treaty, Mr. Kerry said, would demonstrate that “what we do here in the United States Senate matters.” He added, “Don’t let Senator Bob Dole down.”
A handful of Republican senators voted for the measure, notably Senator John McCain of Arizona, in opposition to the other Arizona Republican, Senator Jon Kyl. The others who supported it were Senators Kelly Ayotte of New Hampshire, John Barrasso of Wyoming, Scott P. Brown of Massachusetts, Susan Collins and Olympia J. Snowe of Maine, Richard G. Lugar of Indiana and Lisa Murkowski of Alaska.
Senator Jerry Moran of Kansas praised the treaty in a news release with Mr. McCain in May but voted against it. Senator Thad Cochran of Mississippi voted yes at the beginning of the roll call vote and then switched his vote to no. Calls to the offices of Mr. Moran and Mr. Cochran were not returned.
Senator Harry Reid of Nevada, the majority leader, said the measure would return to the Senate floor in the 113th Congress.
“It is a sad day when we cannot pass a treaty that simply brings the world up to the American standard for protecting people with disabilities because the Republican Party is in thrall to extremists and ideologues,” he said in a statement.
With 38 Republicans casting "no" votes, the 61-38 vote fell five short of the two-thirds majority needed to ratify a treaty. The vote took place in an unusually solemn atmosphere, with senators sitting at their desks rather than milling around the podium. Former Senate Majority Leader Bob Dole, looking frail and in a wheelchair, was in the chamber to support the treaty.
The treaty, already signed by 155 nations and ratified by 126 countries, including Britain, France, Germany, China and Russia, states that nations should strive to assure that the disabled enjoy the same rights and fundamental freedoms as their fellow citizens. Republicans objected to taking up a treaty during the lame-duck session of the Congress and warned that the treaty could pose a threat to U.S. national sovereignty.