SINCE TAKING office, the Bush administration has spent more than $100 million suing the tobacco industry. This week it scuttled its own case just as it was approaching judgment. The episode looks like politically inspired malfeasance, and it should be investigated.

Last month the government put on expert testimony that a comprehensive national smoking-cessation program would cost $130 billion over 25 years. This week, during closing arguments as the eight-month trial wound to an end, the Justice Department suddenly backed off this request -- asking instead for only a $10 billion, five-year program that could be extended. The government thereby reduced by 92 percent the value of a key remedy for the industry's misconduct that the government's own evidence suggested was necessary.

We have not been fans of the federal tobacco litigation. Though it could bring about some useful curbs on industry conduct, it is a poor substitute for what's really needed: a comprehensive federal regulatory structure for tobacco products. That could be accomplished only through legislation, but the Bush administration has refused to seek reasonable regulation for tobacco products, pursuing litigation instead.

The case took a first big hit this year when a federal appeals court threw out the government's request for $280 billion in forfeiture of allegedly ill-gotten profits. After that decision the government pursued other remedies, including the giant smoking-cessation program outlined by its expert witness, Michael C. Fiore. But then -- having spent six years portraying the tobacco companies as racketeers -- the Justice Department unilaterally relieved those companies of the responsibility to spend $120 billion that its own evidence suggests is necessary to help smokers quit.

The decision appears to be the result of political pressure, not a judgment of the legal merits of the case made by the career lawyers trying it. It was made at the political echelon of the Justice Department and imposed on the trial team -- which strongly objected -- by the office of Associate Attorney General Robert D. McCallum Jr. Moreover, the department appears to have pressed its own witnesses to weaken their testimony. Justice Department officials have not offered anything like an adequate explanation for the switch. Mr. McCallum has suggested that the recent appellate court decision requiring that remedies be "forward-looking" required a change. As a consequence, department lawyers suggested to a federal judge in Washington yesterday that their proposed program would cover only smokers affected by legal violations that take place after the court's judgment -- which would leave at least the vast bulk of the 45 million people who smoke high and dry.

It's insulting that they can't at least come up with a better excuse. Democrats on Capitol Hill are calling for an investigation, and rightly so. If the department was behaving reasonably when it introduced evidence that called for the larger figure, it has no business now -- with circumstances unchanged -- refusing to seek the vast bulk of what its evidence suggests the American people are lawfully entitled to. If the administration was going to cave in to its donors and friends in the tobacco industry, it should have done so six years ago. But then, what's $120 billion between friends?