The new Emerson College poll for New York provides some good news for Donald Trump — for now, anyway. With more than five weeks to go before the Empire State’s primary, Trump trounces Ted Cruz for the state’s 95 delegates by more than 50 points, 64/12, with John Kasich only getting 1% despite his big win in Ohio. That puts Trump well over the 50% threshold for winner-take-all allocation, while leaving Cruz and Kasich well below the 20% threshold for any allocation in the event of a plurality. Trump, the home-state candidate, also gets the most favorable marks in...