Wisconsin recall election a bellwether for 2012?

America's biggest ever recall election, in Wisconsin on Tuesday, could reveal trends for the 2012 presidential race, U.S. news media are reporting.

Six state Senate Republicans face recall elections in what has become a referendum on the conservative policies of the state's new Republican Governor Scott Walker, according to Reuters.

The recall elections were prompted by Walker's move to limit public employees' collective bargaining rights. 

Meanwhile, two Senate Democrats face challengers on Aug. 16 and one retained his seat in July.

Reuters reports:

Control of the state Senate hangs in the balance as Democrats need to win three of the six races to take back the Senate if they also retain the two seats up for election on August 16.

Democratic pollster Public Policy Polling found one Democratic challenger with a double-digit lead over the GOP incumbent, the LA Times reports, citing a survey commissioned by liberal blog Daily Kos.

"Two other challengers were behind but within the poll's margin of error," the Times reports.

The polls could shape the agenda for both Republicans and Democrats ahead of the 2012 presidential elections, when Wisconsin may be an important swing state, the BBC reports.

About $30 million has been spent on campaigning in what has been billed as one of the most expensive U.S. state legislative votes in history.

Wisconsin residents have reportedly weathered a near-constant barrage of radio and television ads, and contested districts are littered with candidates' signs.

Walker's move to limit the power of public sector unions prompted massive pro-union protests; Republicans argued the move was necessary to close budget gaps, while Democrats labeled it an attack on unions.