Ohio is one of the most notorious swing states. 538 lists them as Colorado, Florida, Iowa, Michigan, Minnesota, Ohio, Nevada, New Hampshire, North Carolina, Pennsylvania, Virginia, and Wisconsin
Trump won Ohio 51-43. If that swings all the way back into competitive territory, his re-election is doomed anyway. Just because a state is a swing state with a regular Republican (like Ohio or Colorado) doesn't mean it's a swing state when a very abnormal Republican like Trump is running.
I'm not sure we'll ever see a "normal" Republican or Democrat again win a presidential election. Trump has paved a path forward for modern campaigns to run off extreme rhetoric and FUD as a means to mobilize their voting base.
Yes, and Obama won Ohio in 2012 by 3 percentage points. He also won it in 2008. However, George W Bush won it in 2004.