DADT repeal, why did it fail?

Because, like everything going on in Washington right now, they needed something they simply couldn't get- a super majority of 60 or more votes. Technically, it did p. But, right now majority rule means nothing in congress as long as the minority plans to filibuster everything. Filibusters have never before been used this often and prove that we have a bunch of babies running things who, if they don't get what they want, throw tantrums.