Liberals - even without Ted Kennedy, their leading spokesman - are likely to come out of hiding for 1984.
Trends in the economy, fallout from power plays in the Reagan White House, plus the enhanced role of unions in the Democratic nomination process could sharply hone the ideological edge of the 1984 presidential contest.
Record high unemployment nearing 11 percent already is fueling demands on Capitol Hill for jobs programs and other liberal initiatives. Studies by the Congressional Budget Office and the Urban Institute, showing wealth flowing from poor- and middle-class households to the well-to-do as a result of Reagan tax and spending cuts, will also help fire up a liberal challenge to GOP conservative policy leadership.
Contrary to popular notions, liberals are not quite the endangered political species they were made out to be. In the electorate at large, 27 percent of Americans identified themselves as liberals, 32 percent as conservatives, and 41 percent moderates, earlier this year in National Opinion Research Center surveys. This represents a four-point drop for liberals since 1974, a two-point gain for conservatives - but with conservatives peaking in 1978 and declining since then, and liberals gaining since 1980.
And of course, liberals are a potent force in Democratic nomination politics. In 1980, 46 percent of delegates to the Democratic national convention called themselves liberals, 42 percent moderates, and just 6 percent conservative, in a CBS survey. At the same time, rank-and-file Democrats nationally split 24 percent liberal, 42 percent moderate, and 29 percent conservative.
Senator Kennedy's absence will draw forward several other backers of the liberal cause - Sen. Alan Cranston of California, possibly Sen. Gary Hart of Colorado, and former presidential contenders George McGovern and Morris Udall. Some analysts are wondering whether California's Edmund G. Brown Jr. might dust off his White House ambitions.
Liberals will not necessarily rush to the support of former Vice-President Walter F. Mondale. But Mr. Mondale's aides say the former vice-president relishes his current front-runner status. ''I don't know a candidate in the world who doesn't want to be out front all the way to the finish,'' said one campaign aide. ''It sure makes fund raising easier.''
Republican strategist John Sears says Mondale will be able ''in the next six months or so, to tell people, 'I'm going to get [the Democratic nomination] anyway, so you'd better get on board.' But we have to see whether people buy that line.''
As front-runner, with at best a modest margin, Mondale at once becomes a target for his opponents, observe Democratic strategists. ''Stories will be written about Hart, (Ohio Sen. John) Glenn, closing the gap on Mondale,'' says one Democrat. ''It's a very difficult position as the front-runner. Mondale is not known for his 'jugular' instinct. The optimum situation for Mondale would have been for Kennedy to do this a year from now.''
However Mondale and the others fare, the Reagan White House itself could largely determine the ideological tenor of the next two years.
Reagan's siding with one or the other camps in his inner circle - conservative ideologues William Clark and Edwin Meese III on the one side, and moderate pragmatists Michael Deaver and James Baker III on the other - will decide immediate policy issues such as the level of defense spending Reagan will accept, or his strategy with Capitol Hill the next session. But it will also put a strong imprint on the Reagan campaign for 1984, assuming Reagan runs.
At the moment, the member of the inner team seen as most likely to leave is Mr. Baker. ''If Baker leaves, you will see a very different White House,'' one administration official says. ''(Other advisers) would circle the wagons more, try to get the President to dig in his heels on defense and on social spending. The conservative purists would come back to Reagan.
''That would mean a very different type of campaign. The campaign would become more ideological. The Democrats would have a stronger move to the center. Liberals would be mobilized.''
Kennedy was a useful campaign target for the Reaganites. ''Who do you think was the easiest person for the Republicans to raise money against?,'' asks one GOP professional, then answers his question: ''Kennedy!''
Liberals see the political pendulum swinging their way.
''Liberals did quite well in the '82 election,'' says Leon Shull, executive director of Americans for Democratic Action, a leading liberal group. ''The right wing took a pasting.''
''It's pretty clear Reaganomics is generally believed to have failed - or not to have accomplished what (the administration) claimed for it,'' Mr. Shull says.
''The economic issue now is jobs,'' he says. ''And jobs is our issue - a good old-fashioned liberal issue. The other big issue is the military. The country is not enthusiastic for a big military buildup, and fears of nuclear war are building. These are liberal issues, too.
''The big Democratic weakness so far is they haven't convinced the public they have alternative programs - new or old. Kennedy stood for something. That's going to be a loss for liberals.''
Shull sees Mondale and Senator Cranston the clearest gainers from Kennedy's exit - particularly Mondale, whose campaign organization is better set.
''But unless Mondale makes people feel he has a program, has a passion, convinces people he can make it on his own, he's not going to make it,'' Shull says. ''He's got to come out with a clear and decisive program - something people will love or hate.''
If Mondale gains the backing of the National Education Association next August, and possibly the AFL-CIO endorsement next December, he will be hard to beat, Shull says.