Demonstrators yell as Gov. Scott Walker arrives at Empire Bucket in Hudson, Wis., Tuesday, March 15, 2011. ((David Joles/AP))

Statewide, Democrats say they have over fifty percent of the number of petitions they need to recall eight Republican state senators, although they are not over the fifty percent threshold in every district.

“We’re well ahead of schedule,” said Graeme Zielinski, Wisconsin Democratic Party spokesman. “I think in mid-summer, you will have a Democratic Senate.” The party would not release detailed percentages of where the party stood in each targeted seat.

To recall a state senator, petitioners must collect signatures equal to one-quarter of votes from that senator’s district in the last gubernatorial race within a 60-day window. There are petitions out for all 16 state senators currently eligible to be recalled (anyone who has served for more than a year) — and that includes Republicans and Democrats. (Here’s a handy list, along with the number of signatures needed in every district). Once recall petitions are filed and deemed valid, a special election would be held in six weeks time.

Republicans control the Senate by a 19-14 margin, meaning Democrats need to flip three seats to take over.

Of the Republicans targeted, two — Mary Lazich and Glenn Grothman — are in solidly Republican districts and are likely safe. State Sen. Dan Kapanke seems to be the most vulnerable; his district went 61 percent for President Obama in 2008. The other recall districts went for Obama but by smaller margins. Of those, Randy Hopper and Luther Olsen are viewed by Democratic strategists as particularly good targets.

Hopper, for one, is fighting back aggressively. He’s hired Jeff Harvey, a veteran Republican strategist who has previously worked for Rep. Dave Reichert (R-Wash.) and Gov. Chris Christie (R-N.J.). “We have volunteer centers opening up and we have a lot of volunteer efforts throughout the district and we’re making phone calls, going door to door,” said Harvey. “What we’re hearing on the ground is that people are extremely supportive.”

Olsen is taking a more come-what-may approach. “I’m not losing any sleep over it, whatever happens, happens,” he said. “If they get the signatures and they run an election, then I’m up for reelection. That’s just the way the world is right now.”

Republicans haven’t released any numbers from their own recall campaigns. And while the Wisconsin Democratic Party has raised over a million dollars towards the effort through the website ActBlue, Republicans have just in the past few days set up their own fundraising site, with no public goals or totals. (The GOP has also set up a ‘Recall Integrity Center’ to track intimidation or violence from Democrats and their supporters).

“We are going to underpromise and overdeliver,” said Mark Jefferson, executive director of the Wisconsin Republican Party. He anticipates that senators on both sides of the aisle will be recalled, but that at the end of the fight, the GOP will keep control of the state senate.

Republicans are most organized against Bob Wirch in the 22nd district, David Hansen in the 30th district, and Jim Holperin in the 12th district. All three are in relatively vulnerable seats, although all three of those districts went for President Obama in 2008. (No Senate Democrats hold districts won by Arizona Sen. John McCain in 2008.)

Democrats insist enthusiasm for the recall effort hasn’t flagged since the national media spotlight has moved on from the Badger State. “I still hear from a lot of people calling me and asking me how to help,” said Cathy Leaf, a marketing executive volunteering in the 10th district against Sheila Harsdorf.

Republicans believe if they can weather the next few months, their incumbents will ultimately be vindicated. “The Democrats have to strike while the iron is hot, because if they wait for the regular election, people will see that these reforms are the right thing to do,” Jefferson said.

But Olsen acknowledged that there is widespread discontent about the way the budget showdown played out, a feeling that could have political consequences.

“There’s unhappiness all over,” he said. “Everyone’s unhappy with everybody.”