With what we have in the Senate these days, getting 2/3rds approval will be no problem. Mark my words, the closer Obama gets to leaving office, the worse it going to get and there isn’t anyone in congress who will lift a finger to stop him.
Even if it is, BO will simply ignore the outcome and face zero consequences. The majority of congress is undecided on whether they want to keep up the appearances of being a thoughtful debating society for appearances sake or simply a rubber stamp to the emperor.