The idea was for President Carter to sit down to talk legislation and politics with some of his Democratic friends from the House.

It might have helped supply what some of Carter's friendly critics say is lacking - more dialogue and idea-sharing between White House and Capitol Hill.

But Carter's session yesterday with Democrats elected in 1974 - the group billed as the post-Watergate mavericks and reformers - didn't quite turn out as planned.

Some of the president's guests, left cooling their heels while Carter met privately with officers of the class of 94th Congress Democrats, finally gave up and left - less friendly than when they went in.

They grumbled that the friendly White House didn't even provide coffee or doughnuts to help them ease the wait. Rep. Leo Zeferetti (D.N.Y.) quipped that they couldn't even get a glass of ice water.

The meeting had been set for 9.30 a.m. Just minutes before 10 a.m., when the president still had not emerged from his private meeting, at least half a dozen of the waiting congressmen left.

They weren't happy about it, but awaiting them at the House was a roll-call vote on a resolution authorizing Congress to continue in session beyond its statutory July 31 close.

One who left, Rep. Carroll Hubbard (D-Ky.), a former chairman of the 94th class, was miffed. He remembered that in 1975, when the class was new in town, President Ford had them down for breakfast with luminaries such as Vice President Nelson Rockefeller, Secretary of State Henry Kissinger and then Defense Secretary James Schlesinger.

"Quite a contrast with our Democratic White House," he said.

The three dozen democrats who waited until the president could see them were, according to Rep. Bulter Derrick (S.C.), rewarded with "a very positive meeting."

What about his unhappy colleagues?

"If they can't wait for 10 minutes for the president of the United States, they've got a problem. So what. So they're congressmen," said Derrick.

The White House view of the quest for dialogue?

"As often happens, the five minutes the president was supposed to spend with class officers turned into 15," said a congressional liaison assistant.

"It was just unfornate. It is probably something we shouldn't do again. The president is never late to his meetings."