In addition to having the oldest written constitution the US also has one of the shortest. To what can the longevity of so brief a document be attributed?

In the first place, the written part of the English constitution, the Magna Carta, is centuries older than any American document. Two hundred years is hardly " longevity" in historical terms.

In the second place, the utterly misnamed "Patriot Act" has abrogated the Constitution. It is no longer alive, so again, "longevity" seems inappropriate. -------------------------------------------------------------------------------------------------------------- Actually, there is no "written part of the English constitution". Britain is a constitutional monarchy without a written constitution; and though much of British common law can be traced back to Magna Carta, Britain remains bound by parliamentary sovereignty which owes no allegience to any constitution, written or otherwise. Regarding your comment regarding the Patriot Act, you should refer to Article II, Sec.3, Clause 4 of the United States Constitution. You are entitled to emotive political opinions (our constitution guarantees it) but they are not based in fact. My answer to the original question is certainly subjective (as is anyone's) but the US Constitution's longevity is likely due to its simplicity and strict separation of powers.