Trump specifically named Obama as being among those that didn’t reach out to the families of fallen soldiers, saying, “If you look at President Obama, and other presidents, most of them didn’t make calls, a lot of them didn’t make calls. I like to call when it’s appropriate, when I think I am able to do it.” When this was shown to be untrue, Trump backtracked by saying, “President Obama I think probably did sometimes, and maybe sometimes he didn’t.  I don’t know. That’s what I was told. Other presidents did not call. They’d write letters. And some presidents didn’t do anything.”

In the past, Trump had also attacked one Gold Star family for speaking at the DNC, brought a pregnant war widow to tears, and said he didn’t consider McCain a war hero because of his capture, despite having avoided the draft 5 times himself. However, in another instance, he sent a $25,000 personal check to offer his condolences to a grieving Gold Star family.

USA Today – Trump makes false claim that former presidents didn’t call families of slain troops
Business Insider – Trump said he called the families of ‘virtually everybody’ who died in service — but internal White House-Pentagon emails tell a different story