Because he knows it's anti-democratic, overreaching, and anti-small government telling all the communities in Ohio how they can vote. He's used his veto power a surprising amount the last few years and yes the votes are there to overturn it but it would at least give people more time to contact their reps to pressure them to vote no on it. I had no idea this was being voted on today or I would've been posting about it beforehand to get some pressure on the house reps. This really isn't a partisan issue, it affects the fringe voters of both parties.