Be careful, writes political scientist Michael Klarman, excerpted by Andrew Sullivan. There are lots of examples of Constitutional interpretation going against what we would day consider equality.
Yes, you say, but that's all in the past. Considering that for much of its history, the Constitution has been used to uphold exclusion, racism, homophobia, and subjugation of women, and considering that the framers' ideas of church/state separation and/or the role of women or blacks in society were radically different from our own, I'd say that it would be better not to revere the document above our own ability as a society to evolve in our thinking. Leaning on that text has been done on both sides of those arguments, as history has proven.