I'm surprised by the people on here who support Mandel and those who don't. It's most likely he won't receive a primary challenge.
The guy has a big war chest I hear. Also, the Kasich wings seems to be losing steam, the longtime Ohio Republican Chairman (Borges) was suddenly ousted, with even Mary Taylor opposing him. It looks like Mandel has shored up lots of support among all the wings of the Republican primary electorate, but there's still plenty of time I guess.
He's just probably the most reviled politician Ohio. Even many Republicans loathe him.