It’s hard to say which is more offensive — Congress’ abrupt about face on the line-item veto or the reasons given for overriding President Clinton’s scratching of $287 million in military construction projects.

For years, for decades, forever it seems, members of Congress, especially the more conservative breed, kicked and screamed about wanting presidents to have line-item veto authority. It was the only way, taxpayers were told, to protect the treasury from those free-spenders across the aisle.

So in 1996 they got what they wanted and last summer President Clinton started using it. Modestly at first, excising only those unnecessary spending items and narrowly focussed tax breaks that were the most blatant attempts to grease influential bigwigs in the home state.

Save some minor grumbling, everything was fine until fall, when the president snipped away 38 military construction projects in 24 states, projects the Pentagon never wanted in the first place. The thinking was sound: Rather than build the unneeded, any additional military spending should go to raise the standard of living of the nation’s men and women in uniform.

Sound, but with a fatal flaw — military make-work is Congress’ favorite flavor of pork. On Feb. 5, the House voted to override. The Senate followed suit Wednesday.

The reason? The current confrontation with Iraq requires our armed forces to be at the highest state of readiness. The projects? Try an $8.5 million facility for washing vehicles in California. Or a $4.8 million paint shop in Texas.

Picture Saddam Hussein, unfazed by two bristling aircraft carriers on his doorstep, quaking in terror at the thought of impeccably detailed staff cars and gleaming, freshly painted filing cabinets.

Given the hue and cry for the line-item veto, its erstwhile supporters now are strangely silent. One notable, and most welcome, exception is Sen. John McCain, Republican of Arizona, who called the arguments for restoring the cuts “thinly veiled attempts to provide a convenient rationale for Congress’ self-serving, pork-barrel spending.” The nation probably does not need more vehicle-washing facilities, but it sure could use more McCains.

The whole debate, of course, could be moot, as a federal judge two weeks ago ruled the line-item veto to be an unconstitutional breach of the separation of powers. The Supreme Court will rule on the matter in July.

As much as the line-item veto seems like a good idea, here’s almost hoping the high court agrees with the judge. The nation probably doesn’t need anymore paint shops, but it needs this hypocrisy even less.