"It’s ridiculous. Obviously they’re very ungracious people. I did the vaccine. They like to take the vaccine. But even the fake news isn’t giving them credit for that."

"We did the vaccine, saved tens of millions of lives throughout the world by coming up with a vaccine. If I weren’t president, vaccine, you wouldn’t have a vaccine for five years, three to five years would be the minimum. I got it done in less than nine months. And that’s only because of me."  

Said Trump on Fox News this morning, talking to Maria Bartiromo, who asked him how he feels about "how they’re blaming you on everything and they do not attribute the successes that you had to your administration" (Mediaite).

Did Trump give Obama credit for any accomplishment? Did Obama give George W.? I could go back further, but I think it wasn't always this bad, but it's been bad — this extreme partisanship and crude blaming and refusal to give credit — and Trump contributed to the badness. Obviously, he knows it, and he's simply committed to doing his own P.R.