If Intrade had existed, who would it have named the frontrunners for.....

["'Oeps!' De blunders van Rick Perry Indicted"]

Uh....no.

I'm really curious about the 1976 Dem. race.  Anyone know how that one would have been handicapped before the primaries started?

In the Jules Witcover book Marathon, Scoop Jackson is described as the early frontrunner. He'd lined up a lot of labor endorsements and was in the news for taking on oil executives in hearings after the '74 gas crisis. After that would probably be Bayh and the non-candidates the press speculated about, Humphrey and Kennedy. I can actually imagine Intrade being pretty close among these four.

'64 - Goldwater
'88 - Probably Dukakis, but I believe Simon had some buzz around then, and the field was divided enough to keep Cuomo's name in the mix

You skipped '80 for the Democrats in your original post. While Carter would have been the favorite by Jan. 1 (early in the hostage crisis), Kennedy would have had a huge Intrade lead for much of '79.

["'Oeps!' De blunders van Rick Perry Indicted"]

1968 D would've been hilarious - watching Johnson-D go from 90% to 0 in seconds.

RFK was already in the race by the time Johnson dropped out. Given how much Intrade responds to media-hyped candidates like Giuliani and Huntsman, it probably would've been something like LBJ 60/RFK 35/McCarthy 2/Other 3.