Few things are as enjoyable as the anticipation of them, but a political discussion with Pete du Pont is. He has the intellectual insouciance of someone who, having governed successfully and thought seriously, has much to say and nothing to lose by saying it. He is patrician enough to make George Bush look like a hod carrier and optimistic enough to make Jack Kemp seem like Jeremiah. He is 50 and should seek the Republican presidential nomination.

No place under the canopy of Heaven is pleasanter than Delaware, but Delaware is not known as the nursery of presidents. Du Pont declares, with a vehemence compatible with insincerity, that he does not want to change that. So what was he, a former governor and former three-term congressman, doing the other day in Kalispell, Mont., chatting up western Republican leaders? Just being polite, he says. They asked him to drop by.

Perhaps they just like the cut of his jib. It is a presentable jib. But you would have to be as dense as Dr. Watson not to know that du Pont is in demand at Republican conclaves because he is presidential. Fiddlesticks, he says. His only interest is in rescuing the republic from "pessimists." Such as? Bob Dole and lesser lights, such as George Will, for one.

Pessimism, as Du Pont diagnoses it, consists primarily in doubting that the heat of economic growth will evaporate the deficit, and thinking more taxes will be needed. Du Pont's faith in the stimulative powers of tax and budget cutting derives from agreeable experience. When he became governor in 1977, Delaware had the highest income-tax rate and the lowest bond rating among the states. After his eight years, Delaware had a high bond rating and the second lowest unemployment rate, and in his farewell address he felt duty- bound to warn against a cultural contradiction of democracy: prosperity undermines the discipline, especially legislative discipline, that produces prosperity.

He makes good points, but like all points they are good only up to a point. He says, with savage and perhaps unconstitutional cruelty, that trying to cut a deficit by raising taxes is masochistic, "like being a Chicago Cubs fan." He rightly says that tax increases are generally inimical to growth; that governments generally do not succeed when chasing deficits with tax increases; and that five federal tax increases have gone into effect since 1981 and have failed to shrink the deficit.

But if lower taxes are always better, a zero rate must be optimum. The trouble comes when government's bills must be paid. And it will not do to just say: do as Delaware did and cut spending. The federal problem is different. Delaware has no national defense responsibilities and nothing comparable to the "entitlement" component of the federal budget.

Besides, du Pont knows the theory as well as the practice of federal paralysis. He reads serious books, such as economist Mancur Olson's "The Rise and Decline of Nations." From it du Pont derived the theory of "progressive societal sclerosis." Stable societies -- most conspicuously Britain -- accumulate interest groups capable of institutionalizing protections and other privileges. These groups have a growing stake in the status quo. Du Pont believes that one purpose of political leadership should be to reconcile stable societies to "reinvigoration from within," through the wholesome disruptions inflicted by economic growth. These days he is speaking fiercely against the "kamikaze economics" of protectionism, and he has a flair for conservatism that goes beyond bond ratings:

"We have allowed our students to load up on electives at the expense of core subjects, substituting driver education and photography for calculus and chemistry. We have been designing open classrooms when we should have been finding ways to make students open their books at night."

He runs a political action committee that is, appropriately, dispensing political "venture capital." It gives no money to candidates for federal office. It targets 50 congressional districts where Republican presidential and statewide candidates prosper but congressional and state legislative candidates do not. This "farm team" PAC aims to elect state legislators, thereby improving the talent pool of congressional candidates and producing Republican state legislative majorities in time for 1991, the next reapportionment.

This longheaded approach is typical of du Pont, who likes Robert Penn Warren's words: we must go "into the convulsions of the world." Delaware is short on convulsions, but the presidential scramble is not. Could that be why he was in Kalispell? Shucks no, he says. He was in Denver at a fund raiser for his PAC (it followed a Milwaukee fund- raiser) and, heck, Kalispell is so close to Denver.

The distance from Denver to Kalispell is seven times the length of Delaware, the nursery of pessimist-bashers.