The first nationally televised debate debate was between Reagan and Anderson, Carter declined to appear
Since the LP was then on all 50 state ballots and Anderson was not, the National Organization of Women (which sponsored the debates) couldn't come up with any rational metric which would have allowed Anderson to participate while excluding Clark.
It wasn't the NOW gang, but the "League of Women Voters" who sponsored those debates. With your historical revisionism, now you can see why most people consider the Libertarian Party, the party of pot.
Oh gimme a break. Yes, it was the League Of Women Voters, my mistake.
Even Jimmy Carter took note of the LoWV's arbitrary non-standards for inclusion:
"...The League of Women Voters set an arbitrary standard--I never did argue with it--that any candidate to be involved in the debate ought to have at least 15 percent in the public opinion polls. It was an arbitrary standard, but so be it. They were trying to exclude Barry Commoner, who is primarily an environmentalist, and, I think, Mr. Ed Clark, who is a Libertarian. And there are a hundred other candidates, you might be interested to know, in running for President. But they were trying to draw some lines. I don't think any public opinion polls now would show John Anderson to meet the League's standards that they set for themselves. I didn't have anything to do with it...
(from Public Papers of the President, Carter, 1980, pages 2272 to 2273)