It's no secret Republicans ate the Democrats' lunch in Ohio last year. In a state carried by now-President Obama in 2008, under half of the congressional delegation is now Democratic.
It's also no secret Ohio, like many states in the Great Lakes region, is not exactly keeping pace with national population growth. It's sloughing two seats in redistricting, and Republicans will be looking to capitalize. The conventional wisdom says they'll go for a 4-12 map, but that screams "dummymander" the way the Double Down screams "high cholesterol". I think it's likelier they'll eliminate two Republicans and go for a 5-11, though I suspect it will be more of a 5-9-2 in practice.