APThe
Four Democrats broke with their party and voted against the amendment, assuring that the measure would come up short of the 60 votes needed for passage.
Three of those lawmakers — Sens. Mark Pryor of Arkansas, Max Baucus of Montana, and Mark Begich of Alaska — face competitive re-election races in deep-red states next year.
The fourth, Sen. Heidi Heitkamp of North Dakota, was elected to her first Senate term in 2012.