The Wisconsin Supreme Court ruled that Gov. Scott Walker's gubernatorial campaign and conservative groups did not violate campaign finance law during recall elections in 2011 and 2012.

The decision comes just days after Walker officially launched his presidential campaign, but had stalled for more than a year after a lower court found that Walker's campaign did not violate any laws even if it acted as the prosecutors believed, as the Milwaukee Journal Sentinel noted.

The state Supreme Court ruling marks the end of an investigation into Walker's gubernatorial campaign activities.

"It is utterly clear that the special prosecutor has employed theories of law that do not exist in order to investigate citizens who were wholly innocent of any wrongdoing," wrote Justice Michael Gableman in a 4-2 decision for the majority. "To be clear, this conclusion ends the John Doe investigation because the special prosecutor's legal theory is unsupported in either reason or law. Consequently, the investigation is closed. Consistent with our decision and the order entered by Reserve Judge Peterson, we order that the special prosecutor and the district attorneys involved in this investigation must cease all activities related to the investigation, return all property seized in the investigation from any individual or organization, and permanently destroy all copies of information and other materials obtained through the investigation."

Francis Schmitz, the special prosecutor, could push for the U.S. Supreme Court to hear his case, but the Wisconsin court's ruling removes a potential headache from Walker's presidential campaign for the time being.

Walker is in New Hampshire today and is expected to visit a Harley-Davidson dealership this afternoon in North Hampton. It will be the third such motorcycle shop that he has visited since launching his presidential campaign on Monday.