when he said "I'm going to raise your taxes." He went on to say something to the effect that Reagan would also raise taxes but wouldn't tell the people, while he himself would, but the news bites should only him saying, with what looked like an unfortunately gleeful expression, "I'm going to raise your taxes."
I just knew the election was already over when I saw those repeated sound bites, and the Mondale campaign was not clever enough to overcome them. He didn't respond well in the debates either and was too nice to Reagan.
As for Gore, he was "liberal" only in comparison to Bush. The Gore fan club doesn't like to be reminded that Gore was a founding member of the DLC and supported Reagan's military buildup and the wars in Central America. His wife made herself notorious for criticizing sexual innuendos and cursing in pop and rock music.
Part of the reason Mondale lost after Wellstone's death was that the Republican secretary of state (it is said after consultation with Karl Rove) refused to count any absentee ballots for Wellstone as votes for Mondale, while all absentee votes for Coleman were counted as is. My own mother and stepfather were caught up in this, because they had come to visit me in Oregon and had made sure to vote for Wellstone absentee the week before he was killed.
When my brother phoned to say that the secretary of state had ruled that only absentee ballots for Coleman would be counted unless absentees who had voted for Wellstone could a) get a new ballot and fill it out and b) FedEx back to their county courthouse by 8PM on election day, it was already too late. So that was two votes lost for Wellstone. I wonder how many others were in the same boat.
A lesser factor was that by the time the 2002 election rolled around, Mondale had been out of office for 18 years. Younger people didn't know him.
A Green Party candidate was another minor factor.
It was a perfect storm of obstacles.
The enthusiasm for Obama in 2008 (although I never trusted his populist shtick) and the crowds for Bernie Sanders should indicate that Americans have had enough of the Republicans and are ready for something different.