Some Unanswered Questions About Public Employee Unions

I tend to view the debate out over Governor Walker's attempt to strip government employees of various collective bargaining rights as one where liberals and progressives have picked their "side" and not one where they actually believe in the underlying merits of the positions advanced by the unions.  I admit that this may be a convenient interpretation, as I stand firmly on the other side of this issue, and it's common (if unfortunate) to dismiss opponents' arguments as something less than intellectually principled. But in this case, I think the argument that liberals and progressives are making pretextual defenses of unions holds up to objective scrutiny.  I will address that in more detail below, but I approach this debate by asking the following questions, ones that I view as central to addressing the merits of each side's position:

1. Do you think that unions representing public employees will put the priorities of their members over the priorities of the government?  Even if you believe their interests are aligned (a claim that strikes me as largely frivolous and bordering on rationalization) -- assume that a conflict exists.  Which side of that conflict do you believe the union will pick?
2. Do you believe that labor unions involve collusive agreements to fix prices?  Do you think price-fixing typically results in the sub-optimal allocation of resources by those who purchase the services of those fixing prices?  If not, would you have the same reaction to price-fixing by corporations?  Be careful here -- I'm not asking whether you believe that economic distortions caused by price-fixing should be tolerated for unions but not corporations.  I'm asking whether you believe that collective bargaining causes any distortions in the price paid for government employee services (putting aside for the moment whether the countervailing benefits from such a price-fixing arrangement outweigh any negative effects from those distortions).  
3. If the answer to the first question is yes, do you think that the government can provide more or less services for the same amount of money with or without collective bargaining?  
4. If the answer to the second question is yes, what are the countervailing benefits of a union shop that justify the economic distortions of the fixed prices?  The NLRA and other federal laws affecting working conditions were passed during an era when employer abuse -- real abuse, not ten hour days and working in July -- was not uncommon and collective bargaining was viewed as a necessary evil to protect the rights of workers.  Do the same concerns really exist in the 21st Century?  And if they do, do they actually exist in the government sector, where employees always have the recourse of seeking relief in federal court given the fact that managerial excesses by the government could arise to the level of a constitutional violation?  
5. If the answer to the last question is that collective bargaining by public employees will benefit a group that is disproportionately middle class and that this furthers egalitarian goals in general, why shouldn't the poor and middle class as a whole receive the benefits?  Why should they be limited to unionized government employees?
6. If collective bargaining by public employees results in the government having to pay more than it would otherwise have to pay for the services it provides, why would liberals/progressives who want government to play a larger role in society knowingly incur increased costs that will result in the government being able to provide fewer services?  

I answer these questions as follows:

1. Of course unions represent the interests of their members and, if forced to choose, will always represent the interests of the members even if it negatively affects the entity employing the members.  Some people use pejorative descriptions when talking about unions, as if they should be representing something other than their membership.  I take it as a given, however, that their very purpose is to represent their constituents and that they will do so zealously.  I, therefore, do not view this as some "bad intention" by the unions but rather a systemic bias that must always be recognized when they claim they are acting in the public interest (the same criticisms, mind you, apply to defense contractors and many others that point to the public benefits of the services or goods they provide).  
2. If unions are empowered to collectively bargain over wages, they are fixing prices.  And unless the price-fixing is necessary to bring the product to market in the first instance (and here it is not), the agreement on prices will typically result in a higher price for those services than would prevail in the absence of collusion, and that results in a loss of consumer surplus that would otherwise flow to the public at large.
3. In light of the answer to question number 2, I think the answer to question 3 is obvious:  the government will have to pay more for the services it provides as a result of collusive pricing.
4. Here, in my mind, is where the rubber really hits the road in this debate.  I simply do not see any benefits of unionization in the public employment sphere that justify the economic distortions they cause.  I've seen arguments that talk about the importance of seniority for teachers and things of that sort, but those really don't speak to the benefits of collective bargaining.  That's an argument for paying teachers more (in the form of increased security), and those measures can be adopted without providing collective bargaining rights to any particular group.  I've rarely seen any arguments about the benefits public employee unions provide in the administration of government.  And I suspect this is why apologists like Paul Krugman point to public employee unions as a "counterweight" to corporations in terms of influencing the direction of the government.  But even making those arguments gives the game away.  It's tantamount to saying "Well, yeah, public employee unions may make government more expensive, but if we don't have them, who else is going to speak for the poor and middle class?"  If that is what motivates the defense of public employee unions, the solution is to adopt measures that limit corporate influence or that make it easier for individuals to aggregate their resources to protect their own interests.  It is not to make the cost of government more expensive by using public funds to set up a permanent, glorified "pro-government" public relations firm.  
5. If this is nothing more than a battle over who should get a bigger share of the pie, no principled reason exists for affording government employees a larger share at the expense of their private counterparts.  The counter argument to this is that any savings will only benefit the rich and that this is the only practical way to steer benefits toward those with less means.  The flaw in this argument is that if the government has to pay more for the services it provides, the same alleged misallocation of the burden between rich and poor will still exist but now the bill will be higher in absolute terms.  In addition, very few government employees live in actual poverty, so although the challenges they face are real and not inconsequential, any dollars we shift in their direction are dollars that could have been devoted to individuals in greater need.
6. Because liberals and progressives should generally be in favor of a leaner, more efficient government so that scarce resources can be allocated to those in real need, I am left with the belief that their support of public employee unions is, as the Krugman types hint at, that these unions are viewed as an ally in a greater struggle.  If true, that means that liberals aren't backing public employee unions because they genuinely believe in the core functions that those unions provide; instead, they support those unions because they share a common interest in promoting more government.   While that position may be rational if you accept the worldview of a modern liberal or progressive, it doesn't make many of the defenses made by many liberals any less contrived.  

What other questions should be asked?  What are the best liberal/progressive arguments for why these unions are needed in the public workplace (i.e., putting aside their value as political allies)?