The industrial revolution created the opportunity for BOTH ownership and labor to bargain as large units. The middle years of the twentieth century represented the high tide of collective bargaining for America labor -- perhaps because the kind of rough work (factory, warehouse, truck driving) that constituted the core of our economy then CLUSTERED mostly HIGH TESTOSTERONE male workers (one thinks of Jimmy Hoffa's Teamsters) to do labor's core bargaining (and politicking).
As those information economy bells broke up that tough old gang of Jimmy's -- nothing replaced it as a bargaining counterweight to ever more competitive ownership -- in America. In Europe, the over regulation and over protection of labor that was part of the social contract for the first decades after WWII -- as a trade off for allowing more profit to be reinvested into production to speed rebuilding -- has actually overstayed its usefulness leading to two-tier over protection/under protection labor structures in some European nations (which may last until too many people find themselves on the lower tier, the way human nature works).
As Pogo might say: We have met the enemy and he is us -- not the greedy corporations or their Republican slaves who are just doing what they are supposed to be doing: being greedy. 50% of America's private sector workforce may wish they could unionized -- but they mostly lack any sense of the mandatory urgency to do so; or of the unnaturalness of the hurdles manufactured by the current legal scheme under which they may supposedly unionize.
Reconstituting American labor's bargaining power under modern (lower testosterone workers, higher testosterone ownership) conditions can only be accomplished via a bargaining power multiplier used by labor literally all over the world, almost universally in some form in the better paying OECD nations: sector-wide labor agreements (A.K.A., "collective-collective" bargaining).
Sector-wide just backed WalMart's 88 big-boxes out of Germany because their business model didn't work when they had to pay the same as everyone else. (Unfortunately America's WalMart workers do not a price break on housing, real estate or automobiles produced by higher paid workers.)
At the least America can adopt France's and French-Canada's sector-wide "light" wherein everybody working in the same geographic locale does NOT have to work under one commonly negotiated contract (German version) but non-unionized firms MERELY have to abide by the contracts worked out with unionized firms.
A force-multiplying concomitant might be MANDATORY certification elections and RE-certification elections at every workplace every so many years (four?). This would ensure economic democracy American style (fairly balanced, free labor market) while preventing union leadership from ever getting entrenched and out of touch (the most often heard complaint about unions and the most often made explanation for hesitating to unionize).