Up to that point most Americans didn't care about the Middle East, Osama, or terrorist cells. After 9/11 US citizens became much more aware of terrorists groups, suicide bombers and the such. Even though Clinton had a few terrorist attacks the 9/11 attack is one of the deadliest on record with almost 3,000 killed. A lot of the blame can be put on both Bush and Clinton administrations.
What the future holds for the Obama administration I don't know. Will there be another attack, probably, will it succeed? That I don't know.