He isn't exactly a conservative, but he goes after child molesters, the ACLU, terrorists, etc. He does enough good for the left to hate him.
I realize BOR does do some good work on some of society's messes.
I easily see why the Left might hate him...he works for Fox News and he gores a lot of their sacred cows without fear or favor (though he falls way short, because he is definitely more of an old school Democrat at heart and will go soft on some of them by choice.)
It's the part where they peg him as a major figure in the Vast Right Wing Conspiracy that is so silly. LOL