No question about it. The spirit of Washington liberalism is still feisty, resurrected from the 1980 election--which, of course, no one dared mention last night. For everyone here, it was on to '84.

Optimism flowed as easily as the champagne at the Capitol Hill reception given by Americans for Democratic Action, guardian of the liberal flame since Eleanor Roosevelt attended its first meeting at the old Willard Hotel in 1947.

"People simply don't trust Reagan any more and that's significant," said the Rev. Robert F. Drinan, president of ADA. "What we've got is a real circus going on and everyone's so impatient with it. You have the EPA, the deficit and the nuclear issue. It's hideous.

"Reagan is so belligerent on this nuclear thing that he's frightening people. Our coalition these days is broader than the old Roosevelt coalition."

President Reagan, in fact, seems to have done wonders for the cause. Since he came to office, ADA membership has increased from 54,000 to 81,000.

Even college students are jumping on the bandwagon. Cheryl Kagen, a new ADA chapter president, carried her torch all the way from Vassar. "We've always been rebellious, but it's even worse now," said Kagen. "The anti-Reagan sentiment on campus is strong. For a while the conservatives came out of the closet, but not now. They're still scorned on campus."

As far as Hill receptions go, it was standard wheels of brie--yet surprisingly populated for a Friday evening when members generally can't get out of the Capitol fast enough.

In a town where the smell of campaign dollars can light up a political life, even a depressing Washington rainstorm produced a lively group. Those honored were members of the House and Senate who benefited sweetly from ADA's Political Action Committee in the last election.

Take Sen. Paul S. Sarbanes (D-Md.). He couldn't thank ADA enough.

"We have got to get Ronald Reagan out of the White House and that's an absolute!" Sarbanes called out to the crowd of approximately 200 gathered in the Dirksen Senate Office Building.

"I think that people in the country see that this man Reagan promised a rainbow . . . and now they want jobs, they want to feed their families, they want to educate their children--and now I think they find the Reagan policies inhumane," said Sen. Howard M. Metzenbaum (D-Ohio), a self-proclaimed liberal. "There has probably never been an administration less caring. The future has to be a better one because with Ronald Reagan in office it can hardly be worse. People are just not noticing it, they're living it."

As the nation's oldest surviving liberal public interest organization, ADA is perhaps best known for its annual report cards on congressmen, a wonderful publicity grabber that rates a member's liberal (or naughty) voting record on about 20 issues.

Last year, for instance, only 14 Democrats got 100 percent ratings for voting with ADA all the way. Last night Rep. Don Edwards (D-Calif.) appeared to be the only hundred-percenter to make the party.

This weekend, the 75-member ADA board is scheduled to meet here to draw up an alternative nuclear defense policy package to that proposed by the Reagan administration. The board also will lay out the guidelines for determining exactly who in the all-star parade of Democrats ADA will endorse for president in 1984. Sens. Gary Hart (Colo.) and Alan Cranston (Calif.) appear to be vying pretty well for the top spot in ADA's heart.

But then again Drinan seems to have a soft spot for former vice president Walter F. Mondale.

"You know," said Drinan, "Fritz was one of our first college interns. We still have his first pay stub. He's clearly the front-runner, but who knows?"