I respectfully disagree. Although Reagan nominated BG in a technical sense in a speech at the convention, the BG movement was not started by Reagan, rather by millions of conservative grassroots activists like Phyllis Schlafly (Choice, not an Echo). So in the sense that BG captured the imagination and articulated the values of this passionate movement, Dean is doing much the same, don't you think?
PJB is also right about GM and his values. He was pilloried and made fun of in the election (both by his own party and by RMN), but eventually a lot of his ideas (like amnesty for VW deserters) became mainstream in his party.
There was a time when big fat ugly Teddy stood on the steps of the USSC and denounced Roe v Wade when GM was all for it. Well, guess what happened since.
I agree with PJB that Civil Unions will become nationally acceptable in about 10 years, and it that narrow sense, yes Howard the Coward is ahead of his time.