Why vote on cloture instead of just voting on the nominee?
Senate rules.
Because cloture is the question on the table, left over from last night. They could have done it by unanimous consent, but they do need a vote of some sort to be able to move on to the vote to confirm.
my hope is that the Republicans get the 3 justices and Bolton past the Senate and then take off the gloves...rememeber Bolton's negatives are that he is 'too aggressive'--not really an 'extraordinary' enough reason to pull a filibuster (in effect the 7 Democrats have agreed not to stop the Bolton nomination)...take what you can get first and be ready to hang tough to take the rest at a later date...not such a bad deal IMHO.