The only issue is that modern politics in America is a lot more like trench warfare, with lines drawn and and fixed. Opinions on every issue fall along party lines, with a few exceptions.

Given how dysfunctional our political system is, I'll take an outdated and flawed constitution before letting the clowns in power now try and write a better one. Sure, maybe it's not vitally important that the Constitution outlaw the government quartering troops in our houses, but I would not like to see the people behind the Patriot Act, Guantanamo Bay, "extraordinary rendition", and internet wiretapping get a shot at "revising" the fourth and fifth amendments.

As far as what century it applies to, the problems of government are pretty timeless. When one class of people is free to exploit another, the results are the same no matter what century is it.