Shortly after crusty old George Meany, AFL-CIO president, called Jimmy Carter the "most conservative president" since Calvin Coolidge, a key presidential aide confided that Meany was "doing the president's work for him."

The remark, made not at all in jest, was an insight into the thinking of White House insiders as President Carter tries to move the nation into fiscal austerity. Ahead lies the most fateful period of his presidency and perhaps the answer to whether the United States still retains its ability "to act as a nation rather than as a collection of special interests," as he said in his anti-inflation speech.

The presumption that Meany is "doing the president's work" shows that as of today there is very little hedging of bets inside the White House on the president's plan to cut federal spending and reduce the 1980 fiscal year deficit to $30 billion. Despite some ambiguities in the Nov. 7 voting on various referenda limiting state spending and taxing power, Carter's political aides are betting a bundle that the anti-big government, anti-tax crusade is no weekend fancy but an emotional, deeply-ingrained conviction that will sustain Carter's tough fiscal and anti-inflationary policies.

Aside from mixed referenda results, the election pointed toward a rightward political swing that far exceeds the apparent numerical and ideological changes in Congress. Particularly hard for liberal Democratic operatives, for example, was not only the defeat of such liberal stalwarts as Iowa's Sen. Dick Clark and Colorado's Sen. Floyd Haskell. It was also that their conquerors - conservative Republicans Roger Jepsen and William Armstrong - were less than super candidates.

"To say that Dick Clark was beaten just because of the abortion question is to cover our eyes to what really is happening," one perceptive liberal Democrat told us. In short, Clark was thrown out on a whole range of issues on which he predictably and invariably voted the liberal cause, often against the president.

Moreover, the defeat of Clark and other liberals is bound to have a spillover effect on voting habits of other liberal Democrats in the Senate such as Iowa's other senator, John Culver. "We picked up two votes in Iowa, not just one," one Republican-oriented Washington lobbyist told us.

Thus, although the apparent liberal-conservative balance betweent the new and old Senate seems not to be all that different on the surface, deep political currents have been set in motion that will give Carter important assets, tending to move liberals toward the center and centrists toward the right.

In the House, the new liberal-conservative balance is difficult to assess. But one leading strategist in the Democratic Study Group, a liberal pressure group in the House, figures that the results of the election - without any spillover effects - cost the liberals about a dozen votes on economic-ideological issues. In addition, Carter's "new conservative tone," according to another liberal activist in the House, "is having massive impact up here. It is shifting the center of gravity toward the right."

That shift deprives toward the right."

That shift deprives Sen. Edward M. Kennedy, the Democratic Party's tireless liberal leader, of allies in the battles now shaping over Carter's fiscal austerity program. Quiet conversations that have taken place between White House operatives and Kennedy aides signal Carter's probably vain hope to neutralize Kennedy in the battle of the budget and blunt his drive - aided by Meany's AFL-CIO for national health insurance.

For the first few months of the new 96th Congress, Carter will control most of the cards and hold the offensive, but his political dilemma will quickly sharpen: maintaining his spending and anti-inflation lines at the risk of losing one Democratic Party constituency after another. He has lost the leaders of Big Labor; when unemployment starts creeping up again toward 7 percent he will risk losing the card-carrying rankand-file. He was in trouble with the Congressional Black Caucus long before the election; an economic slowdown will hit blacks and other minorities first.

The liberal-intellectual bastions of academia have never loved Carter but they will now get pleasure out of hating him for exempting defense spending from his budget cuts.

Will these Democratic constituencies force Carter to reverse his course before 1980? Carter is betting that the retrenchment mood of the voters, as reflected in the Nov. 7 election, will sustain him. If he is wrong, it could cost him his presidency; if right, it could save his country.