In the private sector, labor and management bargain. If the unions ask too much, the pressure of competition on management mandates that they must hold the line. This is an adversarial relationship with each side supporting its own interests.
With public sector unions, labor sits on one side of the bargaining table, and government (when controlled by Democrats) sits on the same side of the table. The other side of the table, where the tax payer should be, is empty. The tax payer is not even present in the room, and has no representation at all. There is no adversarial relationship.
In the private sector when the unions says “we want more” but pushes for too much more, management can say “we cannot stay in business, so if you want your jobs you have to be reasonable.”
In the public sector when the unions say “we want more” but pushes for too much more, the Democrat on their side of the table simply says “sure”, and “how much more”, and “take even more than that and the taxpayer or borrowing will cover it.” There is no “going out of business” and no pressure on government from “the competition”. Except perhaps international competition, and in that case we can just export our jobs and run up debt as needed.
But the Democrats add, whether spoken or unspoken, “in exchange, we get your votes and political contributions.”
It was not so long ago that Americans realized that public sector unions were unethical, posed the unavoidable conflict of interest described above (union and politician on same side of bargaining table) and just not right.
“It is impossible to bargain collectively with the government.” – George Meany, former head of the AFL-CIO.
When government unions strike, they strike against taxpayers. F.D.R. considered this “unthinkable and intolerable.”
“In terms of accepted collective bargaining procedures, government workers have no right beyond the authority to petition Congress — a right available to every citizen.” – A.F.L.-C.I.O. Executive Council’s 1959 advice.
For more on how this thinking applies to the Scott Walker actions on collective bargaining in Wisconsin, here is a link to a New York Times article, FDR Warned Us.