Andrew Sullivan links to a study that found, among other things, that "the lowest-earning quarter of Americans make nearly one-third of all bike trips." He adds:

I have a bike and no car. And cars are the primary reason we are so indebted to foreign autocracies sitting on sand and oil. But Americans, as usual, don't want to give up their cars (often more than one in a family), and don't want to pay any gas taxes. Then they complain about wars in the Middle East. Driver, heal thyself.

Bikes are cheap, cars are expensive; quads are free, gas costs money. You wanna do something for blue collar workers and the urban poor? Keep building 'em bike trails and extending light rail and make it easier to live in the city without a car, whether you're rich or you're poor, yuppie scum or working class.