Convention on the Rights of Persons with Disabilities
The former senator appeared at an event marking the 25th anniversary of the ADA.
Veterans groups are pushing hard on senators to vote "yes" this time around.
Senators tried to revive a UN treaty that is strongly opposed by many conservatives.
Republicans blocked Sen. Tom Harkin’s (D-Iowa) request to vote on the United Nations' treaty.
Disability advocacy groups have harshly criticized Sen. Bob Corker (R-Tenn.) for saying he wouldn’t...