Wisconsin's Democratic state senators can return home now--their Republican counterparts passed Gov. Scott Walker's union-busting bill last night. Despite major protests at the Capitol in Madison today, the Assembly will likely pass this version of the bill soon. But liberals see a silver lining in this collective-bargaining defeat.

In the hours after the vote, two progressive groups raised $200,000, Politico's Ben Smith reports. And since the Wisconsin fight began three weeks ago, Progressive Change Campaign Committee and Democracy for America has raised $700,000. MoveOn's fundraising page to recall Republican state senators has pulled in $860,000; Daily Kos's has raised $340,000, Dave Weigel adds.

The push recall state Republican legislators is gaining steam now that the bill has passed. Democrats had already collected 15 percent of the signatures they needed to spark a recall over the weekend. And they might try to recall Walker, too, once he's eligible in January. (Wisconsin law says lawmakers have to be in office for a year before they can be recalled.) Salon's Steve Kornaki fantasizes if liberal icon Russ Feingold could be the man to retake the governor's mansion.

And the issue could have national ramifications, The New York Times' Nate Silver argues.  Part of the reason Democrats were defeated so soundly in the midterm elections was the unpopularity of the health care overhaul. Polls indicate that the push to curb union power is just as unpopular, Silver writes. True, many people outside Wisconsin will forget about the battle by the time they vote in 2012. But union households will probably remember.

The number of liberal Democrats who have a "very favorable" opinion of unions climbed from 14 percent to 32 percent. Among union households, the portion who had very favorable view of unions grew from 27 percent to 45 percent. Silver explains:

Wisconsin, then, could motivate these groups to vote — something that they usually do fairly reliably, but did not in 2010. (The share of union household voters in the electorate dropped to 17 percent in 2010 from 21 percent in 2008, according to exit polls.) Although self-described liberals almost always vote Democratic, between 35 and 40 percent of labor households have voted Republican in recent elections. If that fraction decreases to something like 30 percent at the same time that union turnout increases, that would hurt Republicans by a couple of percentage points nationally.

Republicans are less motivated by the union fight, Silver says. That means that the "enthusiasm gap" Democrats suffered last  year could shrink.

As The New Republic's Jonathan Chait notes, though Walker said the legislation was meant to make Wisconsin more fiscally healthy, many conservatives want to scale back union power because they are so crucial to Democrats' electoral success. Wisconsin's State Senate Majority Leader Scott Fitzgerald admitted as much on Fox News:

If we win this battle, and the money is not there under the auspices of the unions, certainly what you’re going to find is President Obama is going to have a much difficult, much more difficult time getting elected and winning the state of Wisconsin.

Chait writes that Wisconsin Democrats will probably pass legislation restoring union power as soon as they recapture a majority. But that's not necessarily a good thing. "The ramifications of parties using their political power in order to try to cripple the opposing party are a lot deeper and more dangerous than Walker seems to be reckoning," he writes.

Update: The Wiscon assembly has passed the bill and sent it to Walker.