Washington — President Reagan's State of the Union speech this week set a tone of conciliation for the 98th Congress, as it turns to the task of lifting the nation's sagging economy.
Lawmakers are arguing over the specifics of programs the President proposed. But both Republicans and Democrats approved of the spirit of his message, which was sprinkled with words such as ''bipartisan'' and ''compassion'' and which even borrowed a favorite Democratic theme, ''fairness.''
Praising the two parties for agreeing on a way to save social security, Mr. Reagan told the joint session of Congress Tuesday, ''I hope and pray the bipartisan spirit that guided you in this endeavor will inspire all of us as we face the challenge of the year ahead.''
''His tone was conciliatory,'' said Rep. Bill Alexander of Arkansas, chief deputy Democratic House whip. ''While he says, 'Let's stay the course,' he makes philosophical changes.''
For the Democrats, the big change is that the President did not attack government as the cause of the nation's woes. ''This man has made a career of blaming the government,'' Mr. Alexander said.
But when the Democrats read over the text of the speech shortly before it was delivered, they discovered a sentence certain to warm Democratic hearts. ''We who are in government must take the lead in restoring the economy,'' it said. When the President delivered that line, the Democrats who had applauded only lightly earlier stood up on cue and shouted their cheers, bringing the Republicans out of their seats, too.
''I think there is a recognition on his part that . . . maybe there is room for the government to move in with some stimulant,'' said House minority leader Robert H. Michel (R) of Illinois, who called the President ''a pragmatic individual'' whose speech was ''appropriate to the times.''
''I was shocked that they admitted that government now has got to be part of the solution,'' said Rep. Tony Coelho (D) of California, who would not deny that he planned the midspeech standing ovation. ''It's 'stay the course' with substantial changes.''
The President, who avoided taking shots at the Democrats, may have problems with members of his own party. Republicans in the Senate, many facing tough reelection campaigns in two years, want cuts in defense spending beyond the $55 billion over five years proposed so far.
Moderate Republicans also express skepticism about plans to freeze domestic spending. ''I didn't see a major change in direction,'' said Rep. Bill Green (R) of New York, pointing out that the President is proposing to hold down domestic spending while ''he is still insisting on all weapons systems.''
But nearly everyone on Capitol Hill concedes that the spirit of bipartisanship is real. Sen. Alan Cranston (D) of California noted the President must of ''necessity'' reach for bipartisan agreement, since the Democrats now firmly control the House and the GOP holds the Senate majority.
A test of the two-party peace pact comes with the arrival next week of the President's proposed federal budget with its projected $189 billion deficit.
''The conciliatory rhetoric and tone (of the State of the Union message) is a good base from which we could build a budget and develop bipartisan support,'' said Rep. James R. Jones (D) of Oklahoma chairman of the House Budget Committee.
For two years, Mr. Jones has been calling for a bipartisan budget, but his calls were drowned out as Republicans pushed through the President's budgets. This year, for the first time, Jones may succeed in finding his ''broad centrist'' coalition.
Shortly before the President's speech, White House chief of staff James Baker III called Jones and offered an olive branch on the '84 budget. ''He said they would not follow the 'my-program-or-nothing approach' of the past,'' according to a Jones aide.
''If both parties are using their brains, they've got to recognize that they can't be responsible for letting this economy fall apart,'' Jones said in an interview earlier this week.