It's the Fourth of July and while we celebrate the founding of our great nation, I'm amused by the dialogue of purity that surrounds our constitution.  Isn't the literal interpretation of any document inherently subjective?  Times have undoubtedly changed the way Americans live.  Is the fight for constitutional purity in the benefit of a progressive nation?  One that strives to lead the world in human rights (whether you think they're "natural," God-given or constitutional), security and peace?  If the constitution wasn't meant to be amended, wouldn't the founders have left that governmental function out of it?  Instead of asking who's more in line with the thinking of the founding fathers -- who didn't conceive of modern medicine, global economies, the internet -- isn't it more important that our contemporary government serve all its citizens instead of an ideal frozen in time?  Reihan Salam writes today (@reihansalam), "I'm a sentimental nationalist. But I can imagine better institutional arrangements than the 1776 Constitution."