The Political Logic Of Repealing DADT

Nate Silver explains it:

[W]hen liberals are scoring Mr. Obama during 2012, his having achieved the goal of repealing DADT would help to reassure liberals that there had indeed been progress made. In some ways, it would represent a nice compliment to health care: one piece of economic reform, one piece of social reform. Both policies, also, proved problematic for Bill Clinton during the first two years of his term, and so achieving them would perhaps provide liberals with some sense of closure.