"This is a common-sense amendment that will secure disability payments for veterans and make sure we are not paying for disabilities that are not truly service-related," said Coburn. 

Sen. Patty MurrayPatty MurrayDem senator: I don't know if Trump 'ever understood' ObamaCare Dems push for more action on power grid cybersecurity Live coverage: Senate GOP unveils its ObamaCare repeal bill MORE (D-Wash.) countered that injuries caused by herbicides like Agent Orange were too difficult to track among former members of the military in order to justify such stringent standards.

“Our military did a miserable job of tracking these exposures," said Murray. "No veteran is going to be able to tell you when or much of this poison, Agent Orange, they inhaled.”

The Senate voted 69 to 30 to table Coburn’s amendment. 

An amendment offered by Sen. Kelly AyotteKelly AyotteOPINION: Democracy will send ISIS to the same grave as communism Kelly Ayotte joins defense contractor's board of directors Week ahead: Comey firing dominates Washington MORE (R-N.H.) to ensure that “wounded warriors” get the benefits of next-generation advanced prosthetics in a timely fashion and an amendment offered by Sen. Barbara BoxerBarbara BoxerTime is now to address infrastructure needs Tom Steyer testing waters for Calif. gubernatorial bid Another day, another dollar for retirement advice rip-offs MORE (D-Calif.) to order a study on the infrastructure of Department of Defense schools were both agreed to by unanimous consent.   

Republican Sens. Tom CoburnTom Coburn'Path of least resistance' problematic for Congress Freedom Caucus saved Paul Ryan's job: GOP has promises to keep Don't be fooled: Carper and Norton don't fight for DC MORE (Okla.) and Bob CorkerBob CorkerLawmakers wary of Trump escalation in Syria Saudis say Qatar demands are non-negotiable Overnight Finance: GOP divided over welfare cuts in budget | Lawmaker loses M on pharma stock he pitched | Yellen says another financial crisis unlikely in our lifetimes MORE (Tenn.) both voted against the underlying legislation. 

The Senate is expected to now move to the House GOP's legislation to cut and cap federal spending while adding a balanced-budget amendment to the Constitution.