One of the keys to Ronald Reagan's success as a politician is that he quickly mastered the fundamental lesson embodied in the legislative adage that "there's no such thing as a one-house bill." Some congressional Republicans say this lesson is being lost as the president's vaunted "tax reform" proposal lurches toward what appears to be election-year oblivion.

As California governor, Reagan learned that prying loose a bill from the then-conservative state Senate was no help if it stood no chance in the more liberal state Assembly. As president, he built popular support for tax cuts and a military buildup that carried the day in the Democratic-controlled House as well as the Republican-dominated Senate.

But all of that was in the first term, when the president's advisers were adept at exploiting Democratic differences and saving Reagan for strategic speeches or negotiations.

Now, with a new team, the president has become a front man. One day, he is thrown to the press corps to explain why his staff has railroaded Health and Human Services Secretary Margaret M. Heckler out of the Cabinet. The next, he is sent on the road to deliver an uninspiring speech on tax reform that treats all opposition as a conspiracy of unnamed "special interests."

Publicly, White House officials pretend that the public is clamoring for tax reform. Privately, they acknowledge that even presidential polls put tax reform far down the list of issues about which Americans are most concerned. A Washington Post-ABC News poll shows that almost six of 10 Americans do not know enough about Reagan's proposal to have an opinion about it.

Republican congressional leaders, who are in touch with the folks back home, screwed up their courage last week and told Reagan to his face that there isn't much public enthusiasm for his tax plan. Furthermore, they said changes being made in the House Ways and Means Committee would penalize corporations and investment and make an already unpalatable bill unacceptable.

Reagan, who acted as if he were hearing this for the first time, told the members of Congress that public response to his speeches has convinced him that the time has come for tax reform.

In fact, as even some White House officials acknowledge, the speeches have been duds. Reagan receives near-saturation media coverage on his tax trips, but much of it is of the "president is coming to town" variety. Judging from the audience response, people are turning out to see the president rather than hear him. In Athens, Tenn., the public-address system failed at key moments of Reagan's speech without producing any protest from the 20,000 persons crowded into the town square.

Mercifully, the "fall offensive" that has yet to claim a victory will come to a summit-induced halt this week with a speech, tentatively scheduled for the Chicago area, in which Reagan plans to reinforce his tax-reform alliance with Ways and Means Committee Chairman Dan Rostenkowski (D-Ill.) and try to persuade Republican doubters that his bill is the wave of the future.

Reagan's communicative powers are intact, as the Soviets are likely to discover at Geneva, but they have not been manifest in the campaign for tax reform. What Reagan has going for him on the tax bill are the efforts of his administration's best Capitol Hill politician, Treasury Secretary James A. Baker III, and his ablest strategist, Deputy Treasury Secretary Richard Darman.

Baker's partnership with Rostenkowski and the latter's determination to dominate the tax issue probably can produce a "one-house" bill that will take Democrats off the tax hook. But it is likely to be a bill that the Republican Senate can't swallow and that forces vulnerable GOP senators to choose between their inclinations and supporting their president in an election year.

Republican senators have long questioned whether they should pass a tax bill that raises no revenue in the face of record deficits. Increasingly, Republican House members are asking why they should pass a tax bill that has little constituent support and helps Democrats capture the high ground on tax reform.

Reaganism of the Week: Speaking to Cincinnati business leaders Thursday and challenging those who predict failure for his tax plan, Reagan recalled: "With the advent of sound tracks for motion pictures in the twenties, Harry Warner, one of my old bosses, of Warner Brothers, said this, 'Who the hell wants to hear actors talk?' "