tl:dr
Portland has provided its amicus support by joining along with the League of Oregon Cities, Association of Idaho Cities, Special Districts Association of Oregon, and the Washington State Association of Municipal Attorneys.
The Martin and Johnson decisions have dramatically undermined the ability of cities in the 9th Circuit to confront externalities of the homeless crisis. In Oregon, House Bill 3115 further tied cities' hands.
These decisions and Oregon law have given unsanctioned campers elevated rights, whether they are our children or felons straight off the bus from Florida. All at the expense of ordinary Oregon residents and cities.
To improve livability in Oregon cities, we badly need the Supreme Court to review Martin & Johnson and for the Oregon Legislature to rethink some of its recent legislation on homelessness, as well as drugs and criminal justice reform (more on that later).
Until that happens, Portland and Multnomah County need to continue to work together to find solutions to the crises on our streets.