40 years in Seattle and this movie (the reasons behind it) were one of the reasons we left. I lived a few miles out of town, in what was once the best suburb of Seattle. With the homeless spread, the spread of illegals and all the drugs, it is just not safe. Granted crime was still low in my area, but the trend is clear. Robbery and home invasions are steadily rising, right along with the tent cities and all their liberal supporters. Add that the cost of living and housing is out of control (People are begging for homes, as they are unaware of the dark secret) and its just not worth it. Given the nice temperate climate (another little secret, yea it rains almost every day, but not so much volume and from July through Sept almost never, rarely below freezing in winter months, and little snow) and you have anice place. plus all the green spaces.
btw - The film mentions how few homeless are seen in Bellevue (across the lake from Seattle), well that's because they chase them to Seattle, as do many locales (that info is directly from a couple LEO's - Leave town, or go to Jail with a point and wink west).
Road Island concept sounds interesting, and I do not think that homeless should necessarily be thrown in with general prison population. So special prison where they take there meds and a carefully outlines out reach program, perhaps. Good luck fighting the rainbows and unicorn politics.
