Motor vehicles are an absolute necessity in the United States, both for economic and personal reasons. If people didn't need cars, they wouldn't buy them. Mass transit will never be able to replace motor vehicles, and trying to shoe-horn an wholly ideologically-driven agenda will blow up in everyone's faces spectacularly.
America isn't Europe. We have spaces between places and are not packed in like sardines.
This is a chicken-and-egg problem. US cities have spent billions on highways and parking and rewrote ordinances to require low density, car-dependent development. You could argue all of that is an honest reflection of voter desires (or at least voter desires of 40 years ago, when most of that stuff happened), but many have undoubtedly bought a car because their environment was designed that way.