UPDATE: Walker Recall Petition Drive Hits the Half-Million Mark

Story updated at 11:40 a.m. CST Thursday to reflect new numbers.

One month to the day after the start of the effort to from office, organizers announced Thursday that they have collected more than 507,000 signatures on recall petitions.

Gathering the majority of the 540,280 petition signatures needed to spark a recall election, Democratic Party of Wisconsin Chairperson Mike Tate told supporters at a press conference Thursday, volunteers will continue to canvass.

United Wisconsin, which is spearheading the recall effort with the Democratic Party of Wisconsin, echoed Tate, setting a new goal for how many signatures it hopes to collect: 720,277. That's one-third of the total turnout in the November 2010 election that saw Walker become the new governor.

"We are well on our way," Tate said a press conference Thursday.

"Scott Walker and the Koch Bros. think they can hold onto power by drowning out our voice with millions in false, misleading television ads. But now, we know that at least half a million Wisconsinites have risen to take back Wisconsin."

Meagan Mahaffey, United Wisconsin’s executive director, said in a statement Thursday, “...The people of Wisconsin are not buying his lies and are moving at record pace to stop Walker’s destruction and recall him from office.”

United Wisconsin launched the recall effort on Nov. 15 and has 60 days to gather the signatures. Petitions are due to the state Government Accountability Board, the state agency that oversees elections, by Jan. 17.

Meanwhile, Republican Party of Wisconsin spokesperson Ben Sparks called the recall effort a "blatant power grab for the Governor's mansion."

"The simple truth is that Governor Walker was elected by an overwhelming majority of Wisconsin voters who were tired of the Democrats’ job-killing agenda, and they have zero desire to go back to the failed policies of the past," Sparks said in a statement to Patch.

News that the recall effort has come close to its signature goal in one month is not surprising. After all, the recall groups announced in late November that they had in the first 12 days of the petition drive.

What remains to be seen, however, is how many of those signatures are valid. Wisconsin law allows people to sign the petitions more than once, and one man told a Milwaukee television station that he put his signature on recall petitions more than 80 times.

In addition, the GAB set off a firestorm this week when one of its staffers said the agency would not automatically strike names like Mickey Mouse and Adolf Hitler from the petitions — as long as those signatures were dated and had Wisconsin addresses.

However, Tate said as volunteers vetted the signatures before Thursday's announcement, duplicate or invalid signatures were thrown out.

"We have a very extensive signature verification process that goes through and make sure that petitions we hand in are valid," Tate said. "There will be some errors on them; there are obviously some people that will sign Mickey Mouse to try to mess with the process and give the Republicans a few good talking points, but I am extremely convinced that not only are we are doing our due diligence, but that there is…hundreds of thousands of residents that have accurately signed these petitions that want to recall Scott Walker.”

The 507,533 signatures collected thus far do not include those gathered to recall Wisconsin Lt. Governor Rebecca Kleefisch, Tate said, though he said they are on track to gather the amount needed.

Tate said organizers would not start to talk about possible candidates to challenge Walker until they reach their new goal of more than 720,000 signatures.

As the target of the recall effort, Walker can raise unlimited campaign funds, whereas state law limits campaign contributions to $10,000 during typical gubernatorial races.