Hmmm. I suppose if Bush decided to push through a flat tax America would be better off, but anything short of that is mere gimmickry given the US tax code. However pushing down the top rate is just sensible economics—it's doing so when you also increase spending massively (Reagan and Bush 43) where you run into problems. Note that tax revenue doubled under Reagan, but he spent so much on defence that it didn't matter. Also note that the rich pay
less as a percent of their individual income, but contribute—as a group—
more of the total tax revenue as it's less worthwhile to dodge paying taxes.
I do know that Rove's staff was looking forward to fighting Dean but I think it was Rove who said it wasn't going to be him. It might be vice versa, I can't remember the source at the moment. Wait. If anyone else remembers someone (Newsweek?) got access to the campaign and did a short book about the inside of the campaigns that was kinda gossipy.
Anyway I think Dean would likely do worse then Kerry in the general (and I continue to insist that either Kerry or Edwards placing second in both Iowa and New Hampshire would count as major momentum given their previous polling positions—given expectations sometimes it's enough to be second) but that the '06 midterms were gonna be bad for the Republicans regardless.
However a big enough victory in '04 may be able to stave off defeat in the Senate (and just think we might have Allan running for President, yuck IMO) although I think the House is probably changing hands.
Assuming, of course, that Iraq proceeds as per OTL which there's no real reason to doubt. The only competent forces in Iraq, and their lessons, have been ignored to this day. There's a couple good articles about the success of some units, mostly due to their commanders, and then I look at the overall picture and just sigh.
Obviously the United States does need entitlement reform. 80% of the budget is taken up by that and defence and it's not like the budget is balanced or anything. Not to mention trillions of dollars of debt, and projected deficits/debt levels that make economists want to kill themselves. Whether the Bush plan would actually curb costs is unlikely given his previous record—prescription drug plan that was nearly twice what he told Congress it was (and he knew beforehand) and either way was completely unaffordable.
I suppose a landslide in '04 depends heavily on his Congressional operators who started to back off from heavy support following that election and Iraq and the like. (Aside: has there ever been a theoretically small government Congress that has ever increased spending this much at the whim of the President?). Crushing Dean may keep them in line, but if Bush's opinion polls drop like OTL they may pull back as they did OTL.
As for Dean winning the general? It's unlikely. Of course he isn't stuck with Bob Shrum

and there's a lot of talent Kerry dumped (Margolis, in particular) but frankly Dean—who was a pretty moderate governor—has to get back to that without being portrayed as a flip-flopper.
I don't if he can but he does have advantages over Kerry. He's tackling the Iraq war and national security head-on, he won't have to deal with Swift Vote, he's better on TV then Kerry.
Who's Dean's VP? I suppose Bill Richardson is looking damn good to him. Edwards… Maybe. Who else was on the list?