On the heels of a U.S. Supreme Court decision last week that overturned total caps on how much individual donors can give to candidates and parties, the Minnesota branch of the Institute for Justice has filed a federal lawsuit that challenges state campaign laws.

Minnesota donors can give to as many individual candidates, parties and political funds they want to. But certain caps do apply to campaigns.

According to Minnesota law, candidates can only accept limited dollars from lobbyists, political committees and large donors. For instance, this year's gubernatorial candidates can only accept $700,000 from what are called special sources.

The plaintiffs, who include State Rep. Linda Runbeck, R-Circle Pines, argue that these limits violate free speech. They're hoping the recent Supreme Court decision in McCutcheon vs. FEC will help bolster their case.

“The law is supposed to treat everyone equally,” Institute for Justice attorney Katelynn McBride said in a statement. “But Minnesota plays favorites by allowing some people to donate twice as much to a candidate as other people."