I think a key to rebuilding the middle class is rebuilding union power---which for many unions/locals will include rebuilding the union itself from the inside out.
As I've pointed out before, collective bargaining in the private sector provides working people the ability to harness market forces to improve wages and working conditions. Any true champion of a free market system believes in freeing workers from the constraints of Government policy ("right to work" laws) which protect a company from market pressures via Government policy. That is why conservatives hate unions---they empower working people and overthrow the hierarchy that the boss is always right.
But the fact the the 1% have bought off politicians to pass laws that protect corporations isn't the crux of the problem in my eyes.
Way too many rank and file members of most unions see the union as an insurance plan rather than a place of solidarity and collective action in which they are able to take back power and gain some control over their own lives.
If union's were stronger--not only would union members have taken to the streets today but company's like UPS would have been bombarding the phone's of lawmakers for fear of the economic consequences of unauthorized work stoppages/work to rule slow downs on their bottom line.
But the fact is union's are not at the levels of organization and militancy needed to align such forces to join together stop bill's like the Right to Work bill shoved through in Michigan today.
The always excellent Corey Robin wrote a post a while back discussing why there are not more union members in the US. I'd boil it down to fear, intimidation, coercion, and the political power of the 1%. Prepare for a decade of labor unrest as we work to rebuild that power and better align the political/economic interests of major players with the concerns and quality of life of working people.
Anyways Corey's post is worth a read: