CHICAGO (AP) -- For months, Illinois Republican gubernatorial candidate Bruce Rauner has owned the airwaves and raised millions more than his March primary opponents.
Now he could be about to face his toughest rival yet: the state's well-funded and politically powerful labor unions.
Officials from several unions say they're close to launching coordinated attacks against the wealthy businessman, who's made standing up to "union bosses" a campaign theme.
They say Rauner is markedly anti-labor compared to the other GOP candidates, state Sens. Bill Brady and Kirk Dillard and Treasurer Dan Rutherford.
The unions have the money to compete with Rauner financially. But their efforts could backfire if they solidify for primary voters that he's the candidate most likely to stand up to organized labor.
Rauner says he's ready for the attacks.