Incumbent Republican Mike Carey holds a fundraising and name-recognition edge in Ohio's 15th District, yet recent Hart Research polling shows Democrat Don Leonard within striking distance, with Carey leading by only four points in the August survey amid a Libertarian candidate drawing double-digit support. The district's suburban Columbus footprint, which includes areas trending less reliably Republican in recent cycles, combined with the broader 2026 midterm environment, sustains trader expectations of a narrow Republican victory. Most probable outcomes cluster in the 3-12 point Republican margin range, reflecting the seat's underlying partisan lean offset by competitive candidate positioning and turnout variables that could still shift final results.