The suggestion here is this became a grass roots tidal wave that those at the top of the unions and Democratic Party couldn't have stopped if they tried. Conventional Wisdom has it that President Obama stayed away from Wisconsin out of fear of being associated with a loser. Possibly. But the lie he told a Green Bay TV station about being too busy to campaign for Tom Barrett says to me Obama never liked this idea. 

Unions had to let the rabid protesting base they were going to do something, anything, no matter how desperate. And that took the shape of the recall. What makes it desperate is not backing off after losing 4 of the 6 senate recalls last year and losing the State Supreme Court race. Perhaps this was a force nobody at the top could stop. What's unclear is if they wanted to.