By Brendan O'Brien
MILWAUKEE (Reuters) - Candidates and volunteers made last ditch efforts to woo voters on Monday, a day before Wisconsin holds the nation's largest ever recall election that could provide an early indication of trends before the 2012 U.S. election.
Six state Senate Republicans face recall elections on Tuesday in what has become a referendum on Republican Governor Scott Walker's conservative policies. Two Senate Democrats face challengers on August 16 and one retained his seat in July.
Control of the state Senate hangs in the balance as Democrats would need to win three of the six elections to have a chance to take back the Senate if they also retain the two seats up for election on August 16.
Spending on the nine elections had reached $33 million by Monday, most of it from outside special interest groups, far eclipsing the Wisconsin record of about $20 million set in 2008 elections including half the state Senate and all Assembly members.
"The spending is just amazing the way it has taken off," said Michael Buelow, research director for the Wisconsin Democracy Campaign, a nonpartisan political spending watchdog.
Victories by Democrats could bolster efforts to launch a recall of Walker next year. Republican wins could freeze that bid in its tracks and give the national party momentum toward defeating President Barack Obama in 2012.
Republicans rode a wave of election victories last November across the United States, and in Wisconsin took control of the state Assembly, the Senate and the governor's office.
A Walker-led drive this year to curb the power of public sector unions as part of a plan to close budget deficits touched off massive pro-union protests and thrust Wisconsin into the national spotlight, leading to the elections.
Some 32 registered interest groups had spent $14.2 million by Monday and the watchdog organization has found unregistered groups had spent at least as much, Buelow said, pegging total interest group spending at $28 million to $28.5 million.
An array of conservative groups including Americans For Prosperity have backed Republican candidates. The union-backed We Are Wisconsin has led interest groups supporting Democrats.
Candidates have reported spending more than $5 million, a figure that will rise when more required reports are filed.
With less than 24 hours to go before the polls open at 7 a.m. local time, Republican and Democratic campaigns redoubled get-out-the-vote efforts on Monday.
"We're canvassing today, going door to door and letting them know where their polling locations are," said Stephanie Wilson, regional director for the Democratic Party of Wisconsin on efforts on behalf of Democratic candidate Jessica King.
King is challenging incumbent Republican Senator Randy Hopper in a rematch of the 2008 election he won by 163 votes.
"We're feeling good," Wilson said. "We're seeing a lot of support."
In the LaCrosse area, incumbent Republican Senator Dan Kapanke was making telephone calls along with volunteers who were making calls and canvassing door-to-door, campaign manager Jen Harrington said on Monday.
"We have the phone bank pretty much filled over here and everyone else is on doors," Harrington said.
Kapanke faces Democratic Representative Jennifer Shilling in a district that has often voted for Democrats.
The Wisconsin elections are making history. There had been only 20 state-level recall elections in U.S. history before 2011 and never more than two in any one year.
Turnout is expected to be much higher than in nonpartisan or special elections and candidates said in the days leading up to the election that few voters appeared undecided.
Also Tuesday, Republican Senator Alberta Darling faces Democratic Representative Sandy Pasch in the Milwaukee area and in western Wisconsin Republican Senator Sheila Harsdorf faces Democrat Shelly Moore, a teacher's union organizer
Pasch was out canvassing Monday around noon with Rep. Peter Barca, the state Senate minority leader who has become a popular figure among state Democrats due to his fervent opposition to the collective bargaining measure that passed this spring. She also planned to go to Shorewood, a village just north of Milwaukee known for quaint shops and progressive politics, to greet shoppers and business owners, and then go door-to-door greeting residents throughout the North Shore.
Republican Senator Luther Olsen faces Democratic Representative Fred Clark in a central Wisconsin district and Republican Senator Robert Cowles faces Democrat Nancy Nusbaum in the east-central part of the state.
(Writing by David Bailey; Additional reporting by Mary Wisniewski; Editing by Greg McCune)