What if the exact same attacks happen on 9/11/00, toward the end of the Clinton presidency and a couple months before the 00 election?
2000 election:VP Al Gore (D-TN)/Sen. Joe Lieberman (D-CT): 339 EVGov. George W. Bush (R-TX)/Sec. Dick Cheney (R-WY): 199 EVThe country comes together behind Clinton, and Gore benefits, winning many of the swing states and avoiding the real life FL drama.
2004 election: Sen. John McCain (R-AZ)/Sen. Rick Santorum (R-PA): 322 EVPres. Al Gore (D-TN)/VP Joe Lieberman (D-CT): 216 EVPeople eventually go sour on Gore and the Dems due to concerns around the war/foreign policy, the economy, and the introduction of same sex marriage.
However, Obama wins in 2008 due to war fatigue/McCain's hawkishness and the 08 economic crash.