It's not as much of a swing state anymore, and the 2018 midterms will show if that trend continues.
If Brown keeps his seat or if they elect a D governor for sure, but if they elect all Republicans and Trump wins it again by similar margins in 2020, then it's gone.
John Kasich is very popular in Ohio, and his successor (Mary Taylor) is polling well, so the Republicans aren't too worried about the governorship. As for Sherrod Brown, he could easily defeated, but Democrat turnout could be high in the midterms.