Kris Warner doesn't understand unions. As a Union member whose grandfather was a president of the AFL, and as someone with a deep loathing for my union, the ability to form unions matters not a whit compared to the utility of JOINING an existing union. The guy talks about a decline from 30% to 11%. That's not about not being able to form unions - that's about people in unions not getting enough benefit to justify the hassle.
I think part of the problem is that the union struggle was so long ago that we don't have an institutional memory of why unions were formed in the first place. Union leadership and management have a power struggle, and the worker see his dues extracted without really knowing where the money is going. The reason states can pass right to work laws will little trouble from the citizens is because unions have become maladaptive behemoths that are often inflexible and intransigent. My best guess is that union membership will continue to dwindle away until workers find themselves exploited to the point that they resurrect the movement anew, and the cycle will repeat.
I know exactly where my dues are going, they're published in the newsletter. My Local president makes $242,000 a year and has had for the past 25 years, the last time he actually worked in the industry. His secretary, who doesn't answer the phone, makes $165k. My residuals go wholly into the AMPTP health fund, which I'm not allowed access to unless I work 400 union hours in a quarter (up from 300 for the past 40 years as of 2008). The theory is that California being a Union state, I should only be able to work Union jobs. Not only that, but Union jobs should be all there is. Lemme tell ya though - I work a show for a major network shot on their own lot and it's been non-union since its inception over a dozen years ago. Pretty much my union dues buy me an all-access pass to a 2nd-rate Lynda.com rip-off as "continuing ed." My personal take is that "union" professons are largely the ones that are going to die.