Omnific One said:
9/11 showed us that we may have varying opinions and beliefs but we still are a very unified nation.
There is nothing better for patriotism then a big disaster like that happening, it makes the people scared and more likely to follow the goverment whatever they plan on doing. If anything patriotism went up 1000% after 9/11, united against what perceived threats (you even had a go at the french at one point for not supporting your war, renaming french fries, etc).
Otherwise im not american, so have no clue, but im under the impression UK is far more likely to be broken up then USA, scots want to break off and if they succeed, wales and northern ireland might get similar ideas.