How Powerful Are the Wisconsin Public Unions?

Why bust the unions? As I said, it has nothing to do with helping Wisconsin deal with its current fiscal crisis. Nor is it likely to help the state's budget prospects even in the long run: contrary to what you may have heard, public-sector workers in Wisconsin and elsewhere are paid somewhat less than private-sector workers with comparable qualifications, so there's not much room for further pay squeezes. So it's not about the budget; it's about the power

There's just one problem with this:  if the union hasn't managed to secure anything in the way of extra wages, benefits, or other concessions for the workers--if it is really true that all these things are close to the minimum required simply to attract workers--then who cares whether the union survives or not?  What "power" is being taken away?