When the CBO scored the bill, it projected that nearly $400 billion slated to be spent on health services would move from discretionary spending to mandatory spending, which is mostly sheltered from the bruising battles that occur each year over where to spend money in appropriations bills.
The Committee for a Responsible Federal Budget, a nonpartisan fiscal watchdog, said a reclassification of nearly $400 billion from discretionary to mandatory would "both reduce the pressure to keep those costs under control and make it easier for appropriators to spend more elsewhere in the budget without offsets."
Those dynamics also applied to the bill when the Senate approved it in June. Nevertheless, senators voted for the measure overwhelmingly.
But, last week more than two dozen Republicans who voted for the bill in June voted against advancing it this time. They sided with Republican Sen. Pat Toomey (pictured) of Pennsylvania, who is seeking a vote on an amendment that he says would not reduce spending on veterans but would prevent spending increases in other nondefense programs down the road.
Senate Majority Leader Chuck Schumer has offered to let the Senate vote on the Toomey amendment with 60 votes needed for passage, the same number that is needed to advance the bill itself.
It's unclear how the delay will be resolved, though Senate GOP leader Mitch McConnell predicted Monday that the bill will pass this week.
Advocacy groups for veterans, a key voting bloc in the upcoming midterm elections, are furious and ramping up the political pressure on lawmakers to act. At a Capitol Hill news conference the day after last week's procedural vote, speakers used terms such as "villains" and "reprehensible" to describe the Republican senators who voted against advancing the measure last week but voted for almost the exact same bill in June.
"Veterans are angry and confused at the sudden change from those they thought had their backs," said Cory Titus of the group Military Officers Association of America.
"You just screwed veterans yesterday," added Tom Porter of the group Iraq and Afghanistan Veterans of America. "Now, we're going to hold them accountable."