Primary elections to recall state senators–the largest campaign in history, driven mostly by Labor and Democratic activists angry at Governor Scott Walker’s destruction of collective-bargaining–are just the first step in wrestling control of the state government back from the right. They start today:

In the balloting on Tuesday, residents in some parts of the state were voting in primary elections that are part of the broadest recall effort in state history. The outcome, to be determined in votes next week and then again next month, will decide whether Republicans, who last fall took control of the governor’s seat and of both chambers of the Legislature, maintain their hold on the State Senate.

The experts who ordinarily offer predictions about how high or low turnout might be had little to go on Tuesday; never before have nine state senators been the subjects of recall efforts all at once, much less in the dead of summer.

Leaders of both parties voiced confidence about the outcomes, but the divide in the Senate is 19 Republicans to 14 Democrats. The flipping of three Republican seats would upend their domination in Madison. The flurry of political commercials now playing — included some financed by national groups — makes clear the size of the stakes.

Watch to see how much this is just Labor’s last gasp–a desperate attempt to reverse the tide of declining unionization in a bastion of progressivism–or, alternatively, the beginning of a resurgence.