Lawmakers on Capitol Hill put aside partisan politics Thursday, with senators from both parties voicing support for the convention.  The U.N. measure was drafted in 2006 and has more than 150 signatory nations.

Republican Senator John McCain spoke before the Senate Committee on Foreign Relations.

"This landmark treaty requires countries around the world to affirm what are essentially core American values of equality, justice, and dignity," said McCain.

The convention's guiding principles include non-discrimination against the disabled, the full participation and inclusion of handicapped people in society, and the right of the disabled to make decisions for themselves.

Within the United States, many of these rights are set forth in the Americans with Disabilities Act (ADA), which was signed into law more than 20 years ago.

"My hope is that U.S. ratification will have a moral impact," said Democratic Senator Tom Harkin.  "My hope is that it will send a signal to the rest of the world that it is not okay to leave a baby with Downs Syndrome on the side of the road to die. It is not okay to warehouse adults with intellectual and psychiatric disabilities in institutions chained to the bars of a cell when their only crime is having a disability. That it is not okay to refuse to educate children because they are blind or deaf or use a wheelchair."Ratification has the backing of the Obama administration. The State Department's special adviser for international disability rights, Judith Heumann, says America's failure to ratify the treaty thus far hampers her ability to advocate for the disabled abroad, including handicapped Americans who travel overseas.

"It is, frankly, difficult to advance the interests of Americans with disabilities and others when we, as the United States, have not ratified the convention," Heumann explained.  "Failure to ratify deprives us of a crucial tool to secure concrete improvements, such as fewer architectural barriers and more accessible air travel."But not all lawmakers back ratification. Republican Senator Jim DeMint argued there is no need for the United States to bind itself to a global pact or submit to international scrutiny of America's treatment of disabled people. He also expressed concern that the convention's stated goal of furthering reproductive rights and health will promote abortion.

No date has been set for a Senate vote, but backers hope the convention will be ratified in coming weeks.