This one of those districts where Republicans REALLY knew what they were doing when they drew the lines. The portion of Franklin county is heavily Dem, but that is completely drowned out by heavily Republican and inelastic rural and suburban areas. It's similar to NC-10, where Republicans took heavily Democratic Asheville and attached it to heavily Republican Charlotte exurb counties to create a district where Republicans are guaranteed about 57% in all situations.
I agree overall, but the Columbus suburbs are a major hotbed of anti-Trump backlash. There are plenty of registered Republicans here who are literally planning to just vote straight-ticket Democratic (with the exception of if Husted is the gubernatorial nominee, folks here still like him) because of Trump (to say nothing of Democrats and independents). The margins in the Franklin County portion would be through the roof with a solid Democratic candidate and there is an outside chance that someone like Goyal could beat Jordan or Mingo in a special election.
I would think that the Dem would need to come close to carrying Delaware county to win.