Kerry probably wins Ohio, New Mexico, Iowa, and the election. Even with the "Rally around the flag" effect that 9/11 had on Bush's approval ratings, he was still only able to win very narrowly versus a pretty poor Democratic candidate, and without 9/11 I don't see him winning.
Assuming 9/11 didnt happen and hypothetically that no terrorist attacks happen up to 2004. Then still a lot of those 11.5 million new voters in 2004 that voted for Bush would turn out. Especially considering a lot of them were evangelicals who turned up because of Bush and also the anti-gay marriage referendums statewide. Along with suburbanites who liked Bush's tax cuts.
without 9/11 then a sizable portion of these voters wouldn't have turned up. So maybe only 7-8 million new Bush voters instead of 11.5. Meanwhile those 1-2 million voters who came out (the anti iraq war kerry voters) wouldn't have turned out.
Also a one million kerry voters probably switched their votes at the last minute because of the Osama tape so assuming 9/11 doesnt happen and Osama was never a factor in most of the 2000s. the popular vote would range from a near tie to 1 million in favor of kerry.
