Light rail works in some cities - it just doesn't work particularly well in Portland. But where parking is really tight, owners of "Smart Cars" have found light rail to be an invaluable transport/parking solution. There's almost always space to be found on a light rail car.
Of course, in Portland, light rail and streetcars almost always have enough room to accommodate your ride; rarely do conditions ever reach the point where people might be inconvenienced if you're not especially careful about how you park. The streetcars running along the newly-opened east-side line, in fact, are popularly referred to as "ghost trains" due to the lack of riders.
But Portland, which pays some nine million dollars a year to operate the things, is pushing hard to gain ridership - and they don't even particularly care what species any particular rider may be. Portland's "leaders" are a tolerant bunch; nobody actually pays to ride their streetcars anyway. And Portland prides itself on its diversity.