I've been at the head of a receiving line at a funeral. In that hour of pain, I heard many things that were offered by people who loved me and wanted to console me, and yet the comments were totally offensive and enraging. "God just loved ____ so much, He decided to take ___ early." Right. I wanted to say.......ok, I won't write what I wanted to say. But, I knew that the person who said that loved me, and wanted to console me. I also realized that most people are not equipped to go through a line like that and say something appropriate. I learned to ignore what they said, to see past what was actually said and listen to what was intended to be communicated.
Trump's comment could have been entirely appropriate depending on the delivery (especially with Kelly's explanation), but out of context it sounds awful to some. I get it. It may have sounded awful to the wife at the time, regardless of how it was delivered. I get it. But, the fact that it was used for political purposes is inexcusable.
Some advice for you all: Going thought a funeral receiving line like that, just say this: "I'm sorry." Maybe "Is there anything I can do?" If you and your audience are the religious type, "We are praying for you." or if not "We are thinking about you." That's it. Keep it short, and just move on after that. You are a fool if you think you will make the person feel better. The only comments they are likely to remember are the obnoxious ones.