Senate Finance Committee Chairman Robert J. Dole (R-Kan.) began a recent speech by waving a blank sheet of paper and proclaiming, "I've just obtained a copy of President Reagan's secret tax plan."

Dole, one of Washington's wittiest speakers, was being deliberately facetious. But his audience of business people laughed nervously, well aware that there are many blank spots to be filled on whatever tax bill Reagan submits in 1985.

A new name might help. "Revenue enhancement" as a euphemism for "tax increase" has been overused. And Republican senators and the White House staff took the steam out of another euphemism -- "tax reform" -- when in 1982 they rammed a tax increase down the throat of the president under the guise of reform.

Now we have "tax simplification" and "base broadening," not to mention the opportunities posed by various sloped and rounded versions of the "flat tax." How about the omnibus Tax Reduction and Perfect Simplification Act of 1985? It could be called "Traps" for short.

Sure, Reagan may fight it for a time on his visits to the White House between ranch stops. Last week, when Office of Management and Budget Director David A. Stockman brought the president the awful news that the deficit for fiscal 1985 would top $200 billion, Reagan whipped out a copy of "A Time for Choosing," the historic speech he gave for Arizona Sen. Barry Goldwater in 1964, and told his troops to stand fast for spending cuts and against tax hikes.

But we have been down this route before. Lurking within the Great Communicator is a great negotiator who knows the value of a strong opening bet. As governor of California, the communicator said he was set in concrete against weekly income tax withholding. He signed the withholding bill, calling attention to the sound of concrete cracking around his feet.

Reality brought Reagan around to withholding. And with a litte help from the Republican Senate, reality eventually will overcome Reagan's beguiling belief that economic growth will cure everything short of baldness.

The power of Reagan as a communicator is that he believes whatever he is communicating, in the tradition of the salesman who has to believe in his product to sell it. The problem with Reagan is that his promises lack quality control and sometimes have to be redesigned after they have left the factory.

The beginning of the latest redesign occurred last week with Stockman's dire report on the deficit. Far from having growth tame the deficit, Reagan was told, the deficit instead will curb growth by sopping up funds needed for business expansion.

On the surface this would seem just dandy for the Democrats, who seem ready to respond to the Reagan landslide by taking revenge against the electorate.

"If there is going to be a tax bill, Ronald Reagan is going to have to say to the American people, this is Ronald Reagan's tax bill," House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) said on the day after the election.

Seemingly, the Democrats remember everything and learn nothing from their losing experiences with Reagan. Those of us who observed Reagan as governor of California where he presided over a massive -- and largely progressive -- tax increase know that he never calls anything "the Ronald Reagan tax bill." He followed the same pattern in 1982, allowing himself to be persuaded at the last moment that the "tax reform" bill was necessary.

Reagan has forgotten that he once thought deficits dangerous, but he has a better intuitive understanding of the American people than his opponents do. He knows, for instance, that people value results more than consistency. In California, when Reagan signed a tax increase he had pledged to oppose, the Democrats thought voters would blame Reagan for going back on his word. Instead, Reagan was given credit for acting responsibly.

When the omnibus whatever-it-is emerges from committee next year with tax simplification, base broadening and a few semi-disguised revenue enhancements, the Democrats will not be able to make points with the voters by saying, "I told you so."

After a few mental handsprings and some more ranch time, Reagan is perfectly capable of going on national television next year and blaming the Democrats for slowing the recovery by refusing to raise taxes and cut the deficit.

This may sound preposterous after the campaign we've just been through and after Reagan's exhortation to his Cabinet last week. But stick around, folks -- you ain't seen nothing yet.