THE CONFERENCE report on the USA Patriot Act reauthorization bill contains one major improvement over the previous version and a few minor ones. The new bill contains strong "sunset" provisions, under which the three most controversial provisions would lapse again after four years, not the seven of the earlier draft. This is no small win for civil liberties. The sunset provisions in the original Patriot Act have given Congress leverage over the past few years to extract information from an administration not known for openness concerning its use of the powers Congress gave it. Insisting that the administration justify itself again relatively soon ensures that Congress will be able to adjust and refine the law as need be.

Yet the conference report remains far from perfect. A bipartisan group of senators is still objecting that it does too little to protect civil liberties, and they are threatening a filibuster, though it is not clear whether they have the votes to sustain one. Some of the changes they are seeking are reasonable and constructive. While the bill does not contain the worst excesses of the House version, which was larded with irrelevant and often terrible policy changes, it still has a fair number of extraneous sections. Some are silly, some ugly.

What makes all this so frustrating is that a consensus bill was surely possible. Indeed, it happened. The Senate version of the bill passed on a unanimous vote, representing broad agreement to grant government authorities the powers they legitimately need while ensuring accountability in their use -- and it didn't contain a raft of irrelevant laws unrelated to intelligence. The members balking at the current bill would do a service if they forced a cleaner, more accountable Patriot Act reauthorization.

Debate over the conference report has focused on a narrow array of civil liberties issues, all quite technical. The rhetoric from civil libertarians makes the stakes here seem greater than they really are. The differences between the various proposals are not huge in practical terms. They are, however, significant. The conference report contains weaker controls on secret warrants for business records in national security cases than the Senate bill did. It also does too little to get a handle on the use of national security letters -- a form of administrative subpoena that the FBI uses in national security cases to obtain records of certain business transactions. These problems are not unsolvable, and it's hard to believe the government is today getting much data through uses of these powers that would be forbidden were they written more accountably.

What's more, sift through the bill and you'll find provisions dealing with tobacco smuggling, establishing civil immunity for folks who donate firefighting equipment to fire departments, establishing new crimes -- some punishable by death -- related to marine navigation, creating a new national security division in the Justice Department, letting Secret Service forensics experts help out in finding missing kids, combating methamphetamine abuse and making life more miserable for people challenging state convictions in federal court. None of this, needless to say, has much to do with protecting America from al Qaeda.

The Patriot Act cannot be allowed to lapse at year's end, and the current bill is much improved over earlier versions. But it could still be a lot better. Precisely because the administration cannot afford to let its powers expire, further improvement should still be possible.