Washington — Under the long stress of recession, Americans now appear to be showing a mixture of grousing and patience in their attitude toward Washington leadership.
First the grousing, which favors the Democrats:
* A clear majority of those responding to the latest Washington Post-ABC survey says it wants President Reagan's budget rewritten.
* In the Gallup Organization's latest survey, Democrats hold a 20-point lead over Republicans in voter preferences for the US House of Representatives elections this fall.
* In Gallup's hypothetical presidential matchup, Sen. Edward M. Kennedy (D) of Massachusetts leads President Reagan, and former Vice-President Walter F. Mondale ties the Republican incumbent.
Next the patience:
* Despite this dissatisfaction, a majority of Americans (56 percent) still think Mr. Reagan's economic programs either will work eventually (21 percent) or need more proving time (35 percent), according to a Roper Organization survey taken April 24 to May 1.
* A minority (39 percent) say time has run out on Reagan's economic experiment, either in the sense the nation can't wait any longer to test the policies (15 percent), or in the conviction Reagan's policies will never work ( 24 percent).
The bottom line, politically speaking, is that the current economic troubles are not blamed on Mr. Reagan . . . yet.
To get at the question of who is to blame for the recession, Roper asked whether it was ''mostly due to the long-term result of 30 years of the government's economic policies,'' or ''mostly the result of economic policies set by the Reagan administration.''
By a 3-to-1 margin, respondents thought ''long-term policies'' responsible for the current recession - ''long-term policies'' 59 percent, ''Reagan policies'' 20 percent, ''both'' 15 percent, don't know, 6 percent.
The judgment that responsibility for current economic straits must be spread more broadly reflects a reasonableness in public expectations evident much of the last decade, observes opinion expert Everett C. Ladd of the University of Connecticut.
Some observers of the presidency, such as Harvard's Richard Neustadt, think that Reagan's approval rating, though declining, is holding up remarkably well given the length and severity of the recession.
In Roper's latest survey of how the recession was affecting families, records for the past eight years were set or tied in every category. Forty-two percent of responding households reported one or more instances of unemployment or underemployment.
Reagan so far is reaping few political dividends from inflation's decline. High interest rates have simply moved up to equal inflation as a threat to the economy, Roper reports. And unemployment now is seen as twice as much an economic threat as inflation.
On basic policy issues, the respondents differ from Reagan on many key points. By more than 2 to 1, they would lower defense spending rather than seek further social spending cuts to keep deficits down. On Reagan's overall handling of the economy, 33 percent approved and 48 percent disapproved in March, a 10 point drop in approval since last September.
''These numbers (reflecting public attitudes on the economy and Reagan policies) suggest he's in trouble,'' says Burns Roper, president of the Roper Organization. ''But he's not in that much trouble.''
''Reagan's done a very good job of preparing people for this economic crunch, '' Mr. Roper says. ''It will be interesting to see how he survives it.
''When he was campaigning, and ever since, he's said we're paying the price for 30 years of mismanagement and excessive spending, and it's not going to be turned around without some pain. And in a sense, it's no worse than he's said it would be.''
One survey question in which some Reagan strategists set great store, is whether America is headed on the right track or wrong track. Nearly 63 percent of the respondents think the nation is on the wrong!track -- a 9 point increase since Reagan's inauguration, Roper says. The ''going in the right direction'' score has faded 5 points to 27 percent.
''The feeling that we are on the wrong track is not simply a political or economic judgment,'' Roper says. ''The two top-ranking reasons for our problems in the public's view - both with significant increases over nine years -- are a 'letdown in moral values,' and 'permissiveness in the courts.' ''