Washington — Sen. Nancy L. Kassebaum knows that when a certain small-business man from her home state of Kansas telephones, he'll be delivering a dire warning on the economy. This week, the businessman was so worried that he called her at home, admonishing that the country is on the brink of bankruptcy.
The constituent urgently asked his Republican senator to endorse a Democratic presidential candidate, Sen. Ernest F. Hollings, who has called for a national freeze on spending.
Senator Kassebaum, a member of the Senate Budget Committee, says she is considering signing up with the freeze idea, though not the candidate. But she is far from convinced that Washington is poised for any major budget reforms, or that the nation is facing immediate danger because of its mounting red ink.
''I personally think that '84 will remain fairly strong,'' she says of the economy. As for dramatic deficit reduction, she says, ''I don't see it coming in a presidential election year.''
That message of nothing major this year, but maybe next, is the clear theme that emerged from the first tortuous attempts at a bipartisan attack on the federal government's red ink.
Economists and some in the Reagan administration fret about deficits, and the stock market is responding with a tailspin. But Washington officials, in their election-year wariness, are not yet in a mood to put their heads together on the problem.
When asked this week if the Reagan administration is making a serious effort to reduce deficits, House Speaker Thomas P. O'Neill Jr. deadpanned, ''I think it's a very serious political effort on their part.''
Democrats have been no less partisan, insisting that they will not sit down in the bipartisan task force again unless it is to discuss their favorite target - defense spending.
Even if the two sides do meet together, they are unlikely to make dramatic proposals.
The Reagan administration has indicated it has no intention yet of making major slashes in the deficit. The President proposed with some flourish a ''bipartisan budget reduction plan'' during his State of the Union message last month. The bipartisan effort would aim to make a ''down payment'' on the deficit of $100 billion over three years, he said.
But the administration now says that the down payment would reduce the 1985 deficit to no less than the $180 billion deficit projected in the President's own budget. ''You never should have taken the $100 billion down payment as an additional $100 billion'' in reductions, said Edwin L. Dale Jr., a spokesman for the administration's Office of Budget Management (OMB).
''Despite some misunderstanding, the aim of the down payment is to make sure the deficits do not go higher than projected in the budget,'' the OMB spokesman said. He also conceded that most of the $90 billion in savings proposed during the first bipartisan task force meeting this week were already in the President's budget or else written into pending legislation.
A chief object of the deficit-cutting panel, according to Mr. Dale, is to help expedite the modest tax reforms and spending reductions already proposed.
House majority leader Jim Wright of Texas, a participant in the deficit discussions, is pushing the Democratic plan to put a knife to Mr. Reagan's proposed 13 percent-after-inflation increase for the military. He is using a plan he attribrutes to former GOP President Ford for saving money by stretching out weapons building.
Congressman Wright also said he is unconvinced that the administration has any long-range plan to reduce deficits. He said that the deficit discussions may give Reagan advisers a ''method for convincing the President'' they must act.
Senator Kassebaum says the public also needs convincing. She says that when she speaks to an audience, she asks how many want to cut spending, and hands go up. She asks how many want higher taxes, and none go up, she says, until she asks how many think the budget should be balanced. Then all hands go up.
She adds that when specific spending cuts are suggested, whether for medicare or cost-of-living increases, the public opposes them. So she predicts that major changes in tax reforms and federal benefit programs will be delayed until after November, when she, among a third of her colleagues, will be up for reelection.
Meanwhile, she says that members of Congress can do a service by talking to their audiences about the need for changes. And she says, ''I'm getting weary of hearing that the President and Tip O'Neill have to sign off'' on any major reform. ''If it's a good package, I can't imagine that the President would not sign it.''