“Don’t ask don’t tell” was one of Clinton’s notions, and Santorum wants re-instate it.
“Don’t ask, don’t tell” was a compromise which was worked out by Colin Powell and Clinton. When Clinton came into office one of the first things he did was to openly admit gays into the military. Don’t ask, don’t tell was only a compromise. As you can see, the gays were not satisfied with that just as they were not satisfied with civil unions.