the original post was a request for information, so I’ll try to give a factual summary of what happened:
Al Gore did in fact win the popular vote in the 2000 election, but as has been pointed out, it’s the electoral college that elects the president. It was a very close election on a state-by-state basis, and that’s generally how the electoral college works – if you win a state, you get that state’s electoral college votes. And the number of those votes is determined by population.
As a result of the closeness of the election, who won in 2000 depends on who won in Florida, which has a fairly large population. The Florida election was very close, and when Bush was given the win, Gore asked for a recount, as was his right under Florida law when an election was as close as this one.
The particulars of the recount went all the way to the Florida Supreme Court (I’m not sure what the grounds of the case were). The Florida Supreme Court called for a recount, which was appealed to the Supreme Court.
The Supreme Court, which has a long history of not interfereing with states’ rights, did intervene, and issued an extraordinary one-time-only (i.e., could not be used as precedent for future cases) decision that it was too late for the recount and they had to go with the original count and Bush was President and that’s that.
The majority of the Court that made that decision were appointed by Republican presidents, several by candidate Bush’s father.
A lot of people, me included, think this was a raw deal.
As has been pointed out upthread, a relatively objective recount conducted by a consortium of newspapers found that if the whole state of Florida had been recounted, Gore would have won Florida, giving him Florida’s electoral votes and the election. (A poster upthread said there is no absolute requirement that electors vote as their state’s citizens vote, which is true, but in point of fact voting as your state votes is how it works in almost all cases.)
There were also a huge number of electoral shenanigans conducted in Florida, where candidate Bush’s brother served as Governor, most notably the extremely inaccurate voter purge list created by a firm that has strong Republican Party ties.
Those are the grounds on which many Democrats consider the election of Bush to have been a sham.
I’m with 'em. Hell, if you’d heard the same set of circumstances about a Third World country election, you’d know the skids were greased.