"Two months before the suicide hijackings, an FBI agent in Arizona alerted Washington headquarters that several Middle Easterners were training at a U.S. aviation school and recommended contacting other schools nationwide where Arabs might be studying." http://www.cbsnews.com/news/fbi-was-warned-about-flight-schools/
Article also mentions there were reports from 1995 that muslims were training to kamikaze into US govt buildings... I expect the GOP to be the grownups in the room, but Clinton & the disputed 2000 election had major part in the laxity before 2001
In reality, it is probably not fair to blame Bush for the pre-9/11 stuff, given
He was only 8 months in, but afterward he totally disrupted the Middle East and wanted amnesty for all on immigration. Considering that was AFTER 9/11 there was lots Bush became responsible for IMO.
Not a good President but I do believe he tried to be honorable.