Hawkins from rightwingnews.com has it right I think.
Republicans voted in unison because it was found they didn't have enough votes to break cloture. So along came McCain/Linds/Martinez/Frist/Hagel with a save face measure of claiming Dem blockage of amendments is why it failed.
Reality? They were going to be humiliated by having a Republican led filibuster block their bill THEY promised would easily pass.
Dems from red states joined them for obvious reasons, it isn't popular at home.
That may be very true. There are stories out today that after the staffers had actually read the bill and realized what's in there a lot of the Senators began to turn against it.