They conducted MANY background checks and found nothing.
When you actually come up with a point, post it. Remember, because you have the right to freely speak, it's often best not to when your speech makes you look idiotic.
Sure they conducted a background check, fool. Just not on this specific topic.
And once again. The background check would have caught some common character flaws (damn I get tired of posting this). Abusive males don't just turn on and turn off at the flip of a switch. They abuse females as a course of daily life. I know this from over 5 years of volunteering as a crime victim advocate, most of which were women from abusive relationships.
If, as thorough as an FBI screening is (likely involving psychological screening as well), didn't catch the flaw, it just isn't one he has.