Federal appeals court hears arguments in John Doe probe into Governor Walker's recall campaign

CHICAGO (AP) — Wisconsin prosecutors on Tuesday, September 9th tried to persuade a federal appeals court to let them to resume their investigation of Governor Scott Walker's recall election campaign, in a case that touches on broader, hotly debated issues about just what constitutes constitutionally-protected political activity.

The arguments before the 7th U.S. Circuit Court of Appeals in Chicago came two months before Walker — a Republican seen as a potential 2016 candidate for president — faces a closely contested re-election against Democrat Mary Burke.

Walker made a national name for himself when he took on public sector unions in 2011 with his measure that effectively ended collective bargaining for most public workers. That fight led to the 2012 vote to recall Walker, which he won.

The recall battle ultimately led to the legal dispute now in the Chicago court.

No one has been charged in the investigation and prosecutors have said Walker isn't a target. Walker and Republicans have dismissed the investigation as a partisan witch hunt against conservative groups, while Democrats say it has revealed serious questions about possible illegal activity by Walker and his backers.

Much of the arguments Tuesday focused on the intricacies of Wisconsin's criminal system. The three judges didn't give a clear sense of which side they might favor.

But Judges Frank Easterbrook, Diane Wood both sounded skeptical about whether a federal court was justified in telling a state how to conduct criminal inquiries.