Thune, Rounds oppose bill that would extend toxic burn-pit benefit for veterans
Those benefits would aid veterans exposed to burn pits in Iraq and Afghanistan.
South Dakota's Republican Rep. Dusty Johnson also voted against the proposal.
The VA denies about 78 percent of disability claims related to toxic exposure.
Critics call the legislation too broad.
Republican Sen. John Thune's office did not respond to requests for comment.
Republican Sen. Mike Rounds says he supports the goal of making sure toxic-exposed veterans receive the benefits they deserve for illness resulting from their service.
However, Rounds says Congress and the VA are overpromising and under-delivering to veterans, especially rural veterans.
"I supported an amendment that would have given toxic exposed veterans the ability to see the doctor of their choice, either in the VA or in the community, without having to go through the broken VA referral process," Rounds said in a statement. "Unfortunately, Democrats who control the Senate would not consider the amendment."