How long have there been presidential primary debates?

[Mr. Morden]

Just curious.  The modern presidential primary system for determining major party presidential nominations has only really existed since 1972, with the McGovern-Fraser reforms.  But over how much of that time has a staple of the primary campaigns been televised presidential primary debates?  Nowadays, these mostly air the 24 hour cable news networks and are largely ignored by the broadcast networks, but of course there was no CNN before 1980.

And were there any cases in which an incumbent president participated in a primary debate?  I'm pretty sure that Bush didn't debate Buchanan in 1992, but did Reagan ever debate Ford?  Or Carter debate Kennedy?

[Mr. Morden]

Oh, and here's a clip from a Bush vs. Reagan primary debate in 1980:

http://www.youtube.com/watch?v=edchtf9MS7g

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

Since at least '68 - Kennedy & McCarthy debated before the Oregon or California primaries and maybe on another occasion.

I'm about 99% certain that no incumbent has participated in a presidential primary debate. In the '80 campaign, Kennedy tried to make an issue of Carter refusing to debate him. I think Carter may have agreed to debates early in the process and then pulled out because of the Iran situation. I don't believe Ford ever debated Reagan either - at least it's never come up in anything I've read/seen.

[Sewer]

I think the 1948 Dewey vs Stassen debate was the oldest.

[The Chairman]

Presidential Primary debates prior to the modern age were held directly at the convention, behind closed doors as far as i know

[Phony Moderate]

There was a Democratic one in 1952 or 1956 too, IIRC.

[minionofmidas]

Of course, these early debates would have been on radio, not tv.

[feeblepizza]

The 1948 Dewey vs. Stassen debate was the first to my knowledge.

[Southern Senator North Carolina Yankee]

There wasn't one in 1940 on the GOP side, atleast that I know of, and I know quite a bit about that nomination process that year. So probably 1948 on the GOP side.

Prior to television, the closest thing would be events where each candidate would come and speak one at a time but not all at once. We still see these today, usually they are held by specific groups or organizations, especially those that are very influential in early primaries.

[JoeyJoeJoe]

I Like Ike 1952:

http://www.youtube.com/watch?v=nG4IX5jBc4Q