msnbc’s Lawrence O’Donnell called out Republicans in the Senate for blocking a treaty to protect people with disabilities.

“Having worked in the Senate for seven years, I think the Senate remains a great institution which has done much, much more to be proud of than the rare occurrences that it should be ashamed of. I don’t usually think that when a vote doesn’t go my way in the United States Senate that the Senate should be ashamed of itself,” said O’Donnell in Tuesday’s edition of The Last Word.

Despite impassioned pleas from decorated veterans Sen. John Kerry and Sen. John McCain, the vote to ratify to the United Nations Convention on the Rights of Persons with Disabilities (CRPD) fell short on Tuesday, 61 to 38. All of the opposing votes were from Republicans.

The CRPD was modeled on the Americans with Disabilities Act, a law passed by the Senate 22 years ago. Similarly, CRPD promoted nondiscrimination and accessibility measures, making sure things like sidewalk ramps and handicapped accessible restrooms are up to par with U.S. standards.

O’Donnell accused these GOP senators of failing one disabled person in particular: former Republican Majority Leader Bob Dole, himself a disabled veteran, who was sitting in a wheelchair on the chamber’s floor.

“Bob Dole reached into their hearts and today found…nothing,” said O’Donnell. “With one word–no–they failed their old friend. They dishonored themselves and they dishonored the United States Senate.”