By law, proponents of the recall campaign -- led by a group called United Wisconsin -- needed to submit 540,000 valid signatures to the state's Government Accountability Board to begin the process of holding a recall vote.
United Wisconsin announced this afternoon that they would easily surpass that figure -- nearly matching the more than 1.1 million votes Walker received in the 2010 election.
The group says their effort will be the "most-participated-in major recall effort in American history." The stack of signatures delivered today, a press release notes, weighs more than 3,000 pounds -- or as much as 158 of the heaviest Wisconsin badgers.
"The collection of more than one million signatures represents a crystal clear indication of how strong the appetite is to stop the damage and turmoil that Scott Walker has caused Wisconsin," Ryan Lawler, a board member for United Wisconsin, said in an emailed statement.
The group is also seeking to recall the state's lieutenant governor, the state Senate president and three other senators, all Republicans.
Elections officials will have at least a month to review the signatures. Walker would also have the opportunity to challenge them, though United Wisconsin says that one of every three signatures would need to be invalid to avoid a recall election.
Once the recall petition is declared valid, an election would be called within six weeks. Democrats would have to put forward a candidate to challenge Walker in that election; if a primary is required, the general election would be held four weeks later.
The effort to unseat Walker began with his successful effort to pass legislation stripping public employees of collective bargaining rights.
Walker, the former Milwaukee County executive who won the governor's office in November 2010 as part of a Republican romp nationally, introduced his anti-union law in February 2011, sparking heated protests from Democrats and labor unions. Democratic lawmakers even fled the state in hopes of preventing its passage, but the law took effect in June.
Opponents of the law first initiated recall efforts against Republican state senators who'd backed the legislation. Two of the six targeted were successfully recalled, leaving Democrats just shy of regaining a majority in the Senate.
Walker has already mounted a campaign to fight the recall effort against him. The Milwaukee Journal Sentinel reported that he was in New York today raising money.
Tea party groups and the national Republican Governors Assn. are also organizing in support of him.
"Gov. Walker tackled Wisconsin's challenges head on, and his plan to turn around Wisconsin is working," Virginia Gov. Bob McDonnell, the association's chairman, said in a statement announcing the organization's "Stand With Scott" effort.
A poll from the Democratic-affiliated Public Policy Polling showed that former Milwaukee Mayor Tom Barrett, who lost to Walker in 2010, was an early favorite among Democrats to take on Walker in a recall election.