Two things have finally turned the tide in such matters:
1. The Ray Rice video
2. Social Media
For years, the NFL has been lightly slapping players on the wrist for domestic violonce offenses - one game suspensions in the cases of Dwayne Carsewell (2004), and Brad Hopkins (2005) and Tony McDaniel (2010), for example.
But then the world saw the video of Rice dragging his unconscious fiancee out of that elevator. And then, of course, we saw the video of what happened inside the elevator.
With that video combined with Social Media, you now have an instant Grand Jury, ready to pass judgment and possessing enough evidence to do so.
Underestimating the impact of those two factors (amazingly, corporations and governments still fail to grasp the impact of social media) the NFL was caught with their britches down and botched the entire affair repeatedly.
People who support these abusers also fail to grasp the import of these factors and have found themselves on the wrong side of history - repeatedly. People who rationalize and justify things like child abuse and abuse of women are finding themselves painted into a corner by their own ignorance being exposed for what it is. Because we now see these things and react to them collectively, the old views of the past are shown up as ignorant and outdated.
So now, if they go ahead and support abusers, they do so at their own peril. They risk being classed and cast among the ignorant.