Here is some more chatter about the recall elections for you.
Good article, besides the disgusting boasting about Scott Walker "being vindicated" when his goons in relatively safe districts are in trouble. The reason Democrats aren't going after the Republicans on collective bargaining is that non-unionized swing voters don't care about it as much as the education cuts and public workers are already more than sufficiently fired about it.
None of these districts are bastions of unions. Kapanke's district is rural farmland that's been progressive since the late 1800s, Darling's is a mix of posh urban neighborhoods and exurbs that care little about "union rights" and much more about their education system etc. Democrats are only avoiding collective bargaining because these are red districts and swing voters are more likely to be swayed by their child's education being gutted than public worker's complaining about something that doesn't affect them.