PITY THE POOR prognosticators confronting this treacherous election of 1990. After a dozen years of easy calls, they have their work cut out for them.

Not since the 1976 presidential election, when voters were tugged between their desire to dump the unelected president who had pardoned Richard Nixon and their doubts about political neophyte Jimmy Carter, has it been so hard to guess the outcome. It took no genius to spot the disillusion with Carter that fueled Republican victories in 1978 and 1980 -- or the appeal of Ronald Reagan's candidacy in the Olympic euphoria of 1984. Nor did you have to be a Sybil to see that the economic populism-Social Security protection arguments that worked so well for the Democrats in the 1982 and 1986 congressional elections had been thwarted by the Willie Horton-Pledge of Allegiance-no new taxes mantra George Bush invoked against Michael Dukakis in 1988.

But this one is tougher. The era of good feelings President Bush engendered after the nastiness of the 1988 campaign lasted for more than a year, punctuated by broad public support for his military actions against Manuel Noriega and Saddam Hussein, and the celebrations of the fall of the Berlin Wall and the freedom of Eastern Europe.

But as the long economic boom ran out of steam and the cost of such governmental follies as the savings and loan fiasco sank in, the public grew increasingly angry with Washington politicians, especially those who seemed far more eager to line their own pockets than tackle the nation's problems. When two of the three top Democrats in the House were forced to resign over financial ethics problems, Republicans thought their time had come.

But then Bush put himself at the very center of the most frustrating of all Washington problems, the budget deficit. He built a bipartisan summit -- and dove off its peak. By dumping his tax pledge, he separated himself from most of his party's candidates, and the budget deal he obtained -- after much grief -- was not one that many voters cheered.

The result has been heightened anguish for candidates of both parties, who have no idea where the voters' ax will fall. With many retirements among the ranks of governors and a number of statehouse incumbents obviously ticketed for defeat, the turnover there on Tuesday will be heavy. Numerically, that's not likely in Congress -- if only because most incumbents enjoy huge campaign cash advantages over their challengers. But expect the unexpected. The voters are going to take it out on someone.

The Post's latest reading on the races is on Page A1 of the news section. The brave men and women whose prognostications you see here in the biennial Outlook Crystal Ball competition deserve your pity -- not your scorn. They don't know what's going on either.

David Broder covers politics for the Washington Post.