Republican lawmakers on Tuesday blocked a treaty to protect people with disabilities from discrimination despite a passionate plea from former Senate Majority Leader Bob Dole, who was severely wounded in World War Two.

The Senate voted 61-38 to pass the United Nations Convention on the Rights of Persons with Disabilities, falling short of the 66 votes needed to ratify the treaty.

The former Republican presidential nominee and Senate majority leader from Kansas tried to persuade Republicans to ratify the treaty and sat in a wheelchair on the sidelines of the Senate floor as lawmakers voted.

Only eight Republicans, including Vietnam War veteran Senator John McCain of Arizona, voted with the Democratic majority in the Senate.

"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," said top Democratic Senator Harry Reid of Nevada.

The treaty was modeled on a U.S. law that is designed to ensure that people with disabilities have equal opportunities in employment as well as state and local government services.