Senate Minority Leader Chuck Schumer called on Graham Platner to "immediately" end his campaign, throwing the Maine Senate race into chaos just four months before Election Day. Why it matters: Maine was Democrats' best opportunity to flip a Senate seat. Now, it has become Schumer's worst nightmare. Schumer and his fellow New York Democrat, Sen. Kirsten Gillibrand, joined a growing list of state and national Democrats urging Platner to drop out. But only Platner can make that decision. "Graham