Washington — Jack Kemp concedes that when he first came to Congress a few years ago he wasn't taken seriously by fellow congressmen or by the press.
The New York congressman can make this concession with a laugh these days--as he did over breakfast March 30--for he is well aware that his political probation period is long since past.
No longer does he read and hear questions about whether a professional football star can make it in Congress. Instead, hardly a day goes by without him being mentioned, in the media and among politicians, as a possible candidate for higher office, including the presidency.
Mr. Kemp still has a number of critics. He holds forth on economics like a veteran economist, though he usually will say at some point in a discussion, ''I'm not an economist.''
Even Kemp's critics see him as an enthusiastic and quick learner when it comes to economics. But they also see him as an oversimplifier. They think supply-side economics, which he strongly promoted to President Reagan, is an expression of this oversimplification.
Kemp, however, says the supply-side approach, embraced mainly in the tax cuts put through by the President, would be lifting the economy into a recovery if faulty monetary policy hadn't undermined it. He blames Federal Reserve Bank chief Paul Volcker for constraining the money supply in a way that keeps the program from fully working.
The congressman told reporters that he met recently with Mr. Volcker and that he, Kemp, ''feels'' that Volcker wants to find some way to bring interest rates down.
Without a drop in interest rates, Kemp says, a mild recovery in a few months will be followed by stagflation.
As Kemp was providing this economic forecast the large turnout of reporters at the breakfast was attentive. All were taking notes. It was clear that the media may not be taking Kemp completely seriously as an economist--but they know he is close to the Reagan administration in the making of economic policy.
Mr. Reagan, journalists here agree, listens to Kemp. And the President has been heeding his advice, first on the shaping of Reaganomics and now on holding the line on keeping the tax cuts on schedule.
So there was a flurry of questions when Kemp said that he thought Volcker ''wants'' to do something about lowering interest rates. Kemp said that he was going to have lunch with Volcker again next week and that he will suggest a new formula, with some different economic reference points, with which Volcker would be able to lower interest rates.
In recent weeks a Monitor check with a number of top Republicans around the country disclosed that there is a considerable amount of support among GOP leaders for a Kemp presidential try, in 1988 if not in 1984.
These politicians say they think Reagan will run again. But if not Reagan, then either Vice-President George Bush or Kemp. Sometimes Kemp is mentioned before Mr. Bush.
Kemp is riding high politically. From quarterback of the Buffalo Bills to president of the United States? Just a few years back that idea would have brought laughter in Washington. No one is laughing today.