But Mark Munroe, the GOP chairman of Mahoning County, home to heavily white, economically struggling — and traditionally Democratic — Youngstown, said that Republican voter registration has “more than doubled” in that county, which gave Trump more than 50 percent of the vote in the primary. The Democratic voter registration advantage over Republican registration in that county has shrunk to only about 6,000, he said, and county election officials confirmed.
“Those Democratic voters and unaffiliated voters who made a point to cross over for Trump [in the primary], yeah I think they’ll be there in the general election,” he said. “If they would go to the trouble to change party registration, get involved, I’ve got to think they’re going to be likely supporters in the fall.”
Republicans are now openly predicting that Mahoning County, which gave Obama 63 percent of the vote in 2012, will flip this year for Trump, saying his tough anti-trade talk resonates in a part of the state that has seen factories close and jobs relocate.

“The fact that a Republican would win one of the most Democratic counties in the state is an indication that some of the normal voting patterns in Ohio are flipping,” said Mark Weaver, a former deputy attorney general of Ohio and now a GOP consultant who expects Mahoning to turn red.