(TNND) — Maine Democrats have just over two weeks to pick a replacement for Graham Platner on the midterm ballot as they try to unseat longtime GOP Sen. Susan Collins and help the national party flip control of the U.S. Senate.“I think the goal will be to pick the person who's most moderate without being so moderate that they alienate progressives, and so it'll be trying to thread that needle,” Rice University political scientist Mark Jones said Friday.Jones said Democrats were effectively trapped with Platner – a scandal-ridden candidate who embraced a liberal, populist message in the vein of Sen....