If there were actual proof that the Russians were able to hack into the computer system of some specific jurisdiction and change actual numbers, then the 2016 would be more controversial.
Until that's been proven, 2000 will be the textbook case of a controversial election:
1. The entire results hinged on one state.
2. The governor of that state was the brother of one of the candidates.
3. The margin of victory in that state was less than 0.01%. (I doubt many of us would declare FULL confidence in any vote if the first count was 5424 to 5423, and then officials refused to double-check themselves.)
4. At the time the state results were declared by the networks, voting was still in progress in 6% of the state.
5. A 3rd-party candidate took a large number of votes--181 times the margin of victory--and there's no doubt that he took votes disproportionately from the losing candidate. (I heard a theory once that 60% of Nader voters would have voted for Gore otherwise, 10% for Bush, and 30% wouldn't have bothered to vote at all.)
6. A poor ballot layout in one county produced some unlikely results, implying that the votes that were recorded were probably not for the intended candidate. (In particular, a precinct consisting heavily of elderly Jews produced a surprisingly strong showing for Pat Buchanan, or as the result was dubbed, "Holocaust survivors for Holocaust deniers".)
7. The final result was basically a coin toss, with the courts shutting down a more thorough count mainly because the process was running up against some hard deadlines. When a Supreme Court decision says that the decision itself should not be cited for precedent, you know that it's not actually great law.
The only reason--at the moment--for considering the 2016 more controversial is that it was more of a middle finger to the democratic concept of "majority rules" than 2000 was. But unlike Bush's hair's-breadth win in 2000, Trump's victory in 2016 is the clear result of election rules that have been in place longer than any of us have been alive.
This. Until anything serious is proven with regards to Russia, 2016 was more of a shock than a controversy.
