From Stateline:

Public employee unions spent most of 2011 suffering setback after setback in negotiating sessions, at state capitols and at the polls. But surveys suggest the labor movement is on the verge of a big win in Ohio next week. If it materializes, it could resonate in other states as well.

An explanation of why unions fared so well in Ohio compared to Wisconsin:

Unions had a similar all-hands-on-deck mentality in the recall elections this summer in Wisconsin, when they fell one seat short of flipping the state Senate to Democratic control. But there are key differences that could go a long way toward explaining why labor seems to be faring better in Ohio.

First, the Ohio law would restrict the collective bargaining rights of police and firefighters, who were exempted in Wisconsin. These groups have been the face of the campaign over SB 5. Both sides have used them in their ads.

…The second major difference between the Wisconsin and Ohio elections is the actual matter on the ballot. While the Wisconsin recall elections tended to be proxy battles between labor and business groups, the campaigns also addressed many unrelated issues. Furthermore, the contests were limited to nine Senate districts. Ohio, by comparison, will have a direct statewide vote on a single question.

Ohio voters repealed the law in November.