You had to have been there in 2000 to see what it was all about. People today think that Gore should have easily won for several reasons (Clinton's popularity, strong economy) and he blew it.
But Clinton's popularity post-impeachment and Senate trial took a hit in the more conservative areas that he had won in 1992 and 1996. The South and Midwest reflected those swings away from the Democrats in 2000. In those areas, Bush was looked as the moral salvation in response to the repugnance of the Clinton years. And the perception of the economy at that time was not all that strong. The stock market was taking big hits from the dot com bubble that had burst (and this continued for a while and did indicate a looming recession which happened in 2001).
Gore was running behind Bush for most of 1999 and much of the 2000 campaign--which caused many to think that Gore would lose the popular vote but could pull it out in the electoral college (!!!). Finally, the Ralph Nader effect reared its very ugly head in places that had gone solidly for Clinton in the previous two election cycles. Add to this, the normal pendulum shift away from the party in power--it is clearly difficult to win a third term in a row.
To their credit, the Gore campaign understood that the Democrats had accumulated a significant electoral vote edge from 1992 and 1996. They focused on the states they thought that they could hold. And they came close to winning the big state trifecta (PA, MI, FL) and the Nader states (all except NH--FL wasn't really considered a Nader state even though 538 votes out of nearly 100,000 could have made the difference). He retained 48 percent of the popular vote (Clinton in 1996 got 49).
Gore's campaign was full of blunders and tactical mistakes (terrible response to the Elian Gonzalez episode, selection of the sanctimonious Joe Lieberman as his running mate, didn't allow Clinton to campaign in FL, didn't focus hard enough in TN or WV, wrote off OH a month before the election when he ended up losing it by only 4 points). And the 36 day post-election process by Gore et al is another matter altogether. But looking back after 20 years, it's really amazing that Al Gore came as close as he did.
With that said, who do you think should've won but blew it?