When I was a kid - and I'm talking, like, 7 - I thought the president sort of "ran" everything. If something somewhere went right, the president must have done a good job of making it happen. If something went wrong, the president must have screwed up. As you grow older you realize that politicians don't control everything that ever happens, unless you become a liberal in which case you either think they do or you think they should.
(The president when I was 7 was Nixon, so this gets complicated for liberals but that's a topic for another day.)
So the 7-year-old version of me might have thought the president was to blame for a train crash in Seattle. But something happened to me that stopped me from thinking such idiotic things. I turned 8. I guess my 7-year-old self could have gotten a job writing for Reuters, because they seem to have a hard time separating the "train crashes in Seattle" thing from the "president must be to blame thing."