They are invisible boundaries wrapped around the city's "bad" neighborhoods--namely, North Portland and the Burnside area. You cannot see them, but the borders around drug and prostitution-free zones are as strong as brick walls. At any time, police can choose to kick out for 90 days anyone suspected of prostituting or dealing drugs.

But, although the exclusionary zones have become an accepted lifestyle for hundreds in Portland, civil rights attorneys are quietly continuing their fight to dismantle them. Next year, some promise, may be the year when the invisible borders fall.

Since a rough form of the drug and prostitution-free zones hit the books in 1995, they have suffered two major setbacks. The first came when a federal appellate court judge in Cincinnati--a city that modeled its exclusion zones after Portland--struck down the code, deeming it unconstitutional.

The second blow came this fall, when a Portland trial court judge agreed that the ordinance interfered with citizens' rights to travel freely though the city, and left far too much discretion to police.

To sidestep these constitutional concerns, the City Attorney redrew the boundaries to encompass two large zones, one blanketing most of Northeast Portland and the other covering most of the downtown blocks that fan off Burnside. The City Attorney also allowed for variances, granting an offender permission to reenter the zone for lawful activities such as meeting with social service providers or going to work. The city's best defense is that exclusions have been effective at controlling crime in various city hot spots.

But watchdogs from the Oregon Law Center are continuing to fight the ordinance in court. For attorney Ed Johnson, the question of constitutionality remains. He believes that the laws have Achilles heels.

"Courts are finding that part of living in a free society includes. . . [moving] freely through public spaces," he explains. "The government has a compelling reason to make the smallest impact possible on people's fundamental rights. Just kicking people out of entire sections of town is pretty broad."