Bad marriages can quickly end in divorce, with the quarreling parties going their separate ways. But once the museum burrows into its new, mostly underground quarters east of Millennium Park, it will be stuck there for decades. And it will set a dangerous precedent, one that promises to wreak havoc on Grant Park?EUR??,,????'???s tradition of open, democratic public space.

?EUR??,,????'??The museum belongs right there,?EUR??,,????'?? insists Mayor Richard Daley, ignoring both the civic outcry against the plan and the call from many quarters to investigate alternative sites. Grant Park is a landscape of remarkable clarity and power, an Edenic swath of green flanked on one side by the inland sea of Lake Michigan and on the other by Michigan Avenue?EUR??,,????'???s man-made cliff of skyscrapers.

For all of its visual majesty, however, the park has been shaped as much by the dry legal prose of judges as by the grand schemes of urban planners. The courts have consistently upheld the historic mandate that the park remain clear of buildings and other obstructions.

It is there in the legal arena, rather than in the Daley dominated political arena where opponents stand their greatest chance to stop this ill-conceived proposal before it tramples on the rulings made by the Illinois Supreme Court around the turn of the last century in response to lawsuits filed by lakefront watchdog Aaron Montgomery Ward.

The tweaks to the architects?EUR??,,????'??? plans are a transparent attempt to comply with the Ward rulings. The height of a glassy entry pavilion along Upper Randolph Street has been cut to 20 feet from 25, the architects say. Skylights in the park, which would bring lights and views to the museum?EUR??,,????'???s vast netherworld, have shrunk to a height of 16 feet from 32. The heart of the museum?EUR??,,????'???s case is that these aboveground additions would consume only 9,610 square feet of park space the size of 1 1/2 tennis courts, the architects say and give back 120,000 square feet of indoor activity space.

The plan practically shouts, ?EUR??,,????'??We are not creating an obstruction!?EUR??,,????'?? Yet a hard look reveals that the architects have yet to resolve the conflicting mandates of creating a vibrant setting for children and families while respecting the Ward court decisions that have been central to maintaining Grant Park?EUR??,,????'???s identity as ?EUR??,,????'??public ground?EUR??,,????'?? a common for all of Chicago?EUR??,,????'???s people. The problem is the aboveground structures, which, even in their shrunken state, will enclose usable space and therefore can be considered buildings. In the 1972 Lakefront Plan of Chicago, the fifth of 14 policies for the city?EUR??,,????'???s lakefront clearly states this goal: ?EUR??,,????'??Maintain and improve the formal character and open water vista of Grant Park with no new above-ground structures permitted

Ward and other property owners along Michigan Avenue gave their consent to the Art Institute of Chicago. Millennium Park?EUR??,,????'???s Harris Theater for Music and Dance followed the Art Institute?EUR??,,????'???s example.

The courts also have indicated that certain structures, restrooms, shelters and bandstands are allowed because they support park activities.

It is the peculiar notion of the Chicago Park District, which would occupy an underground field house next to the Children?EUR??,,????'???s Museum, that the museum?EUR??,,????'???s new home would be no different from such accessory structures. It would, after all, give people something to do in the park.

But by his logic, the Field Museum of Natural History should have been allowed into Grant Park. Instead, as the Illinois Supreme Court ruled in 1909, backing Ward, ?EUR??,,????'??free of any buildings” means ?EUR??,,????'??free of any buildings. “The nature or use of a building is not material,?EUR??,,????'?? the court wrote. The Field Museum settled elsewhere, just outside the park?EUR??,,????'???s southern border on Roosevelt Road.

Although its aboveground presence would be far smaller than the Field?EUR??,,????'???s, the Children?EUR??,,????'???s Museum represents a new threat to Grant Park: a melding of landscape and architecture, where a building is cut into a slope.

The architects claim that their new plan suffers no loss of natural light over the aboveground version, but only the gullible will swallow their idea that oblique views through a sunken courtyard will satisfy those inside. Visitors will see the sky, nearby skyscrapers and trees from the sunken ?EUR??,,????'??learning and play experience?EUR??,,????'?? spaces, but not the grass.

He?EUR??,,????'???s right: The museum should go elsewhere maybe to Pritzker Park in the Loop, or to Logan Square or other neighborhood sites. There it would be more welcome and would boost a neighborhood?EUR??,,????'???s fortunes instead of cramming yet another activity into an already-jammed section of downtown.

Perhaps the Chicago City Council led by Ald. Brendan Reilly (42nd), who has valiantly bucked Daley will hear the popular outcry against this plan and vote it down in June, if only because it threatens their power by overriding the custom of ?EUR??,,????'??aldermanic prerogative.?EUR??,,????'?? Failing that, the courts historically, the champions of open, democratic public space represent the lone barrier against the bad marriage that is about to be visited on Grant Park.