What is it with this Supreme Court?

On the very day that the House of Representatives was struggling with the mess left behind by the flag-burning case, their honors, in another 5-4 decision, said in effect that political patronage is unconstitutional.

The patronage decision will not anger nearly as many people as the flag-burning case, but its damage to the country will be greater. In both instances, the court's narrow majority has taken the precious idea of First Amendment rights and extended it to extremes that not only defy logic but contradict decades of American experience.

Patronage -- the practice of rewarding political supporters by giving them preference in government jobs -- goes back to the very beginning of the Republic. For almost two centuries, it provided most of the energy and muscle for our two-party system.

The dangers are clear when hacks fill responsible positions and competent public servants are subjected to political pressure. To protect against abuse while preserving what was useful, reformers more than a century ago began to pass civil service laws for the federal bureaucracy and for many state and local governments. But it was not until 1976 that the Supreme Court -- or rather, five justices -- intruded into the picture by asserting that all political firings are inherently unconstitutional.

The other day Justice William J. Brennan Jr., who wrote that 1976 opinion, led another narrow majority to the conclusion that all other government personnel decisions -- hirings, promotions and transfers -- must be made without regard to the party affiliation or political history of the individual.

There is a narrow exception for ''policymaking positions,'' but it is clear that the intent -- and effect -- of the decision is to end the patronage system. Maybe I am upset because both the 1976 decision and the recent one involved my home state of Illinois -- the first attacking political firing by Democrats in Cook County, the second political hiring by Republicans in Springfield.

The location is relevant, because Cook County and Illinois have some of the most flourishing and competitive politics in the nation. What is so grating in the Brennan camp's decisions is the obliviousness to the political costs of this judicial intrusion. Indeed, in the 1976 opinion, Brennan asserted that, ''It is not only {individual} belief and association which are restricted where political patronage is the practice. The free functioning of the political process also suffers.''

On that last point, he is flat-out wrong, as retired Justice Lewis F. Powell Jr. pointed out in his 1976 dissent and Justice Antonin Scalia argued even more powerfully in dissenting from the recent decision.

Scalia understands that the parties are at the center of our political system and deserve at least as much consideration as, say, those Republican patronage appointees the Brennan majority saved from firing when the Democrats took over the Cook County sheriff's office.

Listen to Scalia: ''It is self-evident that eliminating patronage will significantly undermine party discipline; and that as party discipline wanes, so will the strength of the two-party system. But, says the court, 'Political parties have already survived the substantial decline in patronage employment practices in this century.' This is almost verbatim what was said in Elrod (the 1976 case). Fourteen years later, it seems much less convincing.

''Indeed, now that we have witnessed, in 18 of the last 22 years, an executive branch of the Federal government under control of one party while the Congress is entirely or . . . partially in control of the other party; now that we have undergone the most recent federal election, in which 98 percent of the {House} incumbents, of whatever party, were returned to office; and now that we have seen elected officials changing their political affiliation with unprecedented readiness . . . the statement that 'political parties have already survived' has a positively whistling-in-the-dark character to it.

''Parties have assuredly survived -- but as what? As the forges upon which many of the essential compromises of American political life are hammered out? Or merely as convenient vehicles for the conducting of national presidential elections?''

The court majority almost willfully ignores two fundamental political realities. Parties are the only mass-mobilization device this nation has developed to energize our democracy. The decline of parties is directly and causally related to the decline of voter turnout.

Mobilization takes manpower, and some of that manpower -- in states such as Illinois -- has been supplied by patronage workers. Removing this resource will make candidates even more dependent on mass-media mobilization techniques, which means money. And, as Scalia pointed out, ''Reliance on money-intensive campaign techniques tends to entrench those in power much more effectively than patronage.'' Today's political-action committee (PAC) managers have shown themselves far less willing to gamble on the outs getting in than the job-seeking precinct workers of the past.

The court has fired at the wrong target and has wounded the political system.