Three hundred thousand bikers spent Memorial Day weekend roaring around Washington in tribute to our war dead, and I stood on Constitution Avenue Sunday afternoon watching a river of them go by, waiting for a gap in the procession so I could cross over to the Mall and look at pictures. The street had been closed off for them and they motored on by, some flying the Stars and Stripes and the black MIA-POW flag, honking, revving their engines, an endless celebration of internal combustion. A patriotic bike rally is sort of like a patriotic toilet-papering or patriotic graffiti—the patriotism...