The Senate held two votes on health care last night. McCain voted yes for both of them. The second one was “On the Motion (Motion to Waive All Applicable Budgetary Discipline Re: Amdt. No 270 )” Here’s a link to explain.
“The Senate parliamentarian had previously ruled that provisions in the draft did not comply with the rules of the budget reconciliation process. This vote was to waive the conditions required by the budget reconciliation process. Waiving those requirements requires a 3/5ths vote. This vote failed and the proposal was ruled out of order.”
Basically they tried to vote on this proposal by a simple majority, by saying the proposal was only budgetary in nature. This was shot down, so the Senate tried to vote to negate the rules so they could vote the proposal in with a simple majority anyway. That vote ultimately failed, but McCain did vote in support of it.