THERE ARE an estimated 20,500 lawyers in Washington, D.C. If President Reagan is able to deliver on his promise to abolish government regulations, do away with federal regulatory agencies and cut back on the bureaucracy, many of these fine men and women will soon find themselves out on the streets.

Washington has always been a super growth area for lawyers. For every law that Congress put on the books, 20 government lawyers were needed to write the rules interpreting what the legislators really had on their minds.

Then once the regulations were passed, thousands of lawyers in the private sector had to be hired to figure out ways of getting around them.

But the future looks very bleak now for the legal profession in the capital if Reagan has his way.

Masterman, a lawyer who makes $250,000 a year, was bitter.

"Most of the lawyers in Washington worked for Reagan's election, and now he's trying to eliminate every federal regulatory agency that kept us alive."

"But," I pointed out, "you've been telling me for years that the bureacracy in Washington was a mess and it was impossible to get anything accomplished. Didn't you realize that you people would be the first victims of deregulation of government agencies?"

"I'll admit we didn't think it through. But every president promises to cut back on big government and eliminate red tape when he comes into office. tNo one has ever been able to do it. We had no reason to believe that Reagan would succeed where others failed."

"How did he do it?" I asked.

"He was very clever," Masterman said. "The laws are still on the books, and so are the regulations. But he's put out the word that his people are not going to do anything if corporate America doesn't observe them. He also has Stockman chopping out any funds for policing the law. Without government inspectors, companies have nothing to fear from the regulations any more, and therefore they have decided they don't need lawyers to protect them. Fear is what kepy my firm in business."

"Give me an example," I said.

"Take the Department of Interior. The Supreme Court ruled the other day that strip miners were obligated to put the land back in the shape they found it. But they left it to the secretary of the interior to see that this was done. Secretary Watt's answer was to close down the regional offices that were in charge of inspecting strip mines. Who needs a lawyer to protect you from the environmentalists when you have an interior secretary like that?"

"Then what you are saying is that although the laws are on the books, the fact the administration intends to ignore them is the main reason you people are going out of business?"

"Of course that's what I'm saying," Masterman said angrily. "I have cases with regulatory agencies that have been dragging on for years. One with the Environmental Protection Agency paid for my rent, three lawyers and five secretaries, and we still had two years to go before we were going to get a decision. The other day I got a call from a client who told me to forget the case. No one is afraid of the EPA these days."

"I guess all your white collar-crime business is shot to hell, too."

"It's nonexistent. I don't know one corporate executive who even talks about staying out of jail any more."

"How on earth are you going to keep alive if the government doesn't care what your clients do?"

"It isn't going to be easy. A lot of us are trying to hang on by handling the new defense contracts."

"I guess there is still big money in that."

"There is not much money in drawing up a contract with the Pentagon. But if we can survive long enough, there should be some big fees when the military contractors are forced to sue the government for their overruns."