YOUNGSTOWN — The hand-lettered sign on the red pickup parked near the Hillary Clinton rally Saturday night at East High School told the story. The painted plywood proclaimed the area as “Ground Zero” for Donald Trump crossover voters. And that’s why Clinton’s first campaign trip after last week’s Democratic National Convention in Philadelphia zipped straight to the Mahoning Valley, where a host of Democratic voters in Ohio’s March primary crossed over and took a Republican ballot.adcelannotate = {"mobilepaywallcategory" : "MOBILE_PREM-LOCAL","nativepaywallcategory" : "NATIVE_PREM-LOCAL"};