HELENA, Mont. (AP) — A constitutional challenge to Montana’s campaign contribution limits is back in court with the potential to affect the 2016 primary elections. It’s the same case that disrupted the 2012 governor’s election. Federal judge Charles Lovell set an April 18 hearing on the case and a May 23 trial, if needed. That sets up the possibility of another ruling by Lovell on contribution limits weeks or months before an election.