He said at some point that he beat his ex, but I don't remember the exact circumstances of that. He also posted a picture of a girl cowering in a corner with a black eye with the shadow of a man falling on her with the caption "go make me a sandwich" or something like that. He posted this with a comment about how he didn't support women working or gender equality or something.
Recently he implied that women who didn't act like ladies deserved to be beaten up (put in their place, as it were). And also claimed that adultery was worse than violent abuse, which in turn seems to imply that it's ok to beat your partner if she cheats on you.
He was just generally quite creepy.
Plus what others said here about he was an asshole.
He also used the terms "hussy" and "prostitute" to describe a White House intern who accused JFK of inappropriate behavior:
https://uselectionatlas.org/FORUM/index.php?topic=148475.25And said that an actress who endorsed Romney "enjoyed taking her clothes off for money":
https://uselectionatlas.org/FORUM/index.php?topic=161197.msg3459623#msg3459623