Jeb Bush's failure in 1994 was substantially due to a gaffe he made on his campaign, when asked by reporters what his administration might do for Black Floridians he said: “Probably nothing”. Jeb Bush got 4% of the African-American vote that time around. Running in 1998 OTOH he got 17% of the black vote by... not blowing them off like he did in 1994, I guess. As for GWB, just have him have a gaffe of his own in 1994 and Ann Richards will beat him(it was also a close race).
Nominated in 2000, he will obviously pull Florida as well as more moderates and Hispanics. However he will also be more vulnerable on his right flank to defections to Buchanan. Given his Hispanic wife, his less Southern persona and his not being an Evangelical... West Virginia, Tennessee and Arkansas might all be vulnerable to Al Gore(and maybe even Louisiana, given how David Duke did so well there just a decade prior).
Assuming he does win, S.V. Date(
http://www.washingtonpost.com/wp-dyn/content/article/2007/01/19/AR2007011901364_pf.html) describes his likely presidency well. He is pretty undeniably superior to his brother(I maintain that GWB was suffering the early stages of mental deterioration- not based on partisan hackery, but based on observing his crisp debating in 1994 relative to his debating in 2004. At minimum his communication skills had deteriorated, and it seems a safe assumption if they had declined that other brain functions had declined as well). For one thing Jeb would be a lot more aggressive in promoting his education reforms- unlike GB he wouldn't back down on the inclusion of school vouchers in his reform effort. His record on dealing with a hurricane in Florida also suggests he would deal with Katrina much better then Bush did.
Longterm he we probably see the Republicans a lot stronger among Hispanics especially if he can succeed in his immigration reform proposal, though I doubt he would since the backlash would be even greater against him given his Hispanic wife- unless he's smart and pursues immigration reform right off the bat in 2005 rather then a DOA Social Security reform. Couple this with a better handling of Katrina and possible better handling of Middle East wars and we probably don't see the landslide against the Republican congress in 2006.
Come the financial crisis and we'll see how a Jeb Bush and Republican controlled senate(and possibly they'd still control the house) handles the financial crisis. No idea whether he handle it better or worse.
The rise of Internet political crazies might be delayed without any controversy in Florida, but I think they'll still find each other.
Nope, 9/11 will inevitably trigger them.