The Bush legacy:
1) Lied us into an unnecessary war that's cost a trillion dollars and 4,000+ US lives.
2) Inherited budget surpluses and converted them to $400+ billion annual deficits.
3) Allowed 9/11 to happen despite numerous warnings to the effect Al Quaeda was going to hijack airliners & crash them into buildings.
4) Sanctioned torture & abrogated Geneva accords, thus putting US military lives at risk worldwide.
5) Office leaked the name of at least one covert CIA agent to the media for political purposes.
6) Sat in his Crawford ranch house & did nothing while New Orleans drowned.
7) Fired about a half-dozen US Attorneys (all Republicans) for refusing to do Karl Rove's bidding and turn the US Dept. of Justice into a political branch of the RNC.
There are others but that's a pretty good (bad) list to start with.