What would cause a wheel to wobble?

There are several reasons and some of them depend on your definition of "wobble". None of the scenarios are good. 1) the wheel is bent, which signifies some kind of accident. 2) the tire is extremely out of balance, which will have a negative effect on the whole steering system. 3) the whole front end is totally shot, very expensive repair. Why does the power steering pump need to be repaired/replaced. They almost never go bad even with a minimum of maintainence. I'd think a while before buying this car. (personal opinion)