When the trial balloons began rising off the White House lawn after the election, it was especially clear why people hate "pragmatist" Republicans. Everything remotely specific that President Reagan said in his campaign, the message emanating from the vicinity of David Stockman went, was a lie: We can't grow our way out of the deficit. The boom isn't going to keep up its pace. We need new taxes. There isn't much waste left in domestic programs. We don't need all this growth in defense. And, by implication: We sure fooled 'em on November 6, didn't we?

Conservative Republicans who really believe the reverse of all those propositions obviously don't like seeing their mandate betrayed after just a week; Democrats, for their part, are steaming over the possibility that Reagan will now enact Walter Mondale's campaign promises, of which he lately made so much fun. And if you're into being infuriated, Stockman's explanations for his behavior are just as bad as his conclusions. Why, other than to avoid making Reagan look like a liar, was it necessary to "discover" an extra $30 billion of deficit for it to be an important problem -- wasn't $170 billion enough? Is there anyone who will really believe that the reason Stockman didn't tell Reagan his numbers were wrong was that there just wasn't a spare five minutes in the presidential schedule until after the election?

One possible reaction to Stockman is counter- trial ballooning, and this is what the Ed Meese/Heritage Foundation report/spending cut/percent of GNP gambit (far less deceitful, by the way) is about. But the commoner response is just to be mad at Stockman, and at Reagan if he goes along, for being such public hypocrites. What happens next will depend in large measure on the workings of this hypocrisy factor.

The old-line liberal Democrats, for instance, want what Stockman wants, but may not play ball (or in the official terminology, form a bipartisan consensus) just out of pique. As Tip O'Neill says fairly often, why help Reagan? Moderate Democrats and Republicans, especially in the House, are terrified that they'll vote for the responsible deficit package only to see someone run at them from the right in '86, using recycled Reagan speeches from '84. Even conservatives, many of whom are more worried about the deficit than they let on, are hemmed in by the hypocrisy factor -- they can't go to their old-time favorite solutions because Reagan, forgetting 25 years of his own speeches, ruled them out during the campaign.

So everyone who is mad has a perfect right to be. Alas, everyone should now go ahead and let hypocrisy triumph anyway, because the alternative is worse: demonstrating a capacity on the part of our political system simply to refuse to face serious problems.

Let's set aside for the moment the scenario in which the deficit triggers a disastrous chain of economic events; even so, the deficit is still alarming, as a symbol of our inability to decide what we want our government to do. We think taxes are too high and services too low, and to deal with the mismatch between our desire for services and our unwillingness to pay for them, we make up explanatory myths. We tell ourselves that welfare accounts for a third or half of all federal spending when it's really more like 1 percent, or that Social Security and Medicare are self-funded insurance programs.

America is dominated by large bureaucratic organizations, the most important of which is the government. In every organization, the temptation exists to shift the focus away from what it's supposed to do -- its output -- and toward internal imperatives generated from within the organization. The moment an organization succumbs to this temptation, it stops really working. If it's an auto company, it keeps making big cars whethe market clearly wants small ones; if it's a computer company, it uses its own microprocessor chip rather than the industry standard, and watches helplessly as nobody buys. In every case in which an organization seems to jump off a cliff, if you inquire as to why, you'll find that everything it did made perfect sense as a response to internal pressures; its great mistake was in letting these blot out external reality.

The deficit isn't the only way for the government to go through this routine, but it's certainly a prime example. For an American politician at this moment, raising taxes or cutting defense or entitlements are fatal propositions, thanks in large part to Reagan's efforts. Hence, the deficit -- it's a result of the fear of losing elections crowding out serious considerations of what the government is supposed to do.

For the whole long minuet of pragmatists and purists to end by ignoring it -- and cutting $35 billion in wasteful spending without raising taxes comes under that heading -- it will mean that the forces of unreality have triumphed and become dominant. That's unreality, not "optimism." Not only that, it will be a victory so important as to be possibly permanent, and that is terrifying.

I know that conservatives regard realism as a code word for liberalism; the kind of realism I'm talking about, though, can cut many ways ideologically. In another incarnation, it would take the form of endless new programs that give money to high-turnout voters. It could lead to refusal to face a military threat -- history shows clearly that we're capable of that. Its highest and worst expression in the past, of course, was bloody disunion.

It is absolutely crucial that our government remain moored in the idea that what it does will have the logical consequences. Compared with the danger of losing that mooring, what's a little hypocrisy?