Many people are blaming McCain, however people who hate Trump like to blame him for everything, like what happened with Obama. "It's been raining for 10 straight days!!...thanks Obama!"
And no, they don't need 60, they just need 51.
Oh yeah, and "why didn't McCain vote?" you ask? 'Cause he's a RINO..that's an easy one.
If McCain votes, that's 51, and it passes. If McCain doesn't vote it's deadlocked, and Pence votes, and it passes. Thus, McCain won't vote.