It's like he said in the campaign, he could literally walk out on the street and start shooting people and he wouldn't lose a vote. The military families who supported him will forgive him (or more likely don't even accept that he said it). The new narrative from Fox News is that the congresswoman who heard him say it has a bad voting record when it comes to vets. So in their world it's okay that he said it because the person who heard it is bad.
It's the same playbook they used when W was in power. He did something horrible (I forget what it is now) and they attacked the reporter who broke the story for being a homosexual.