John Oliver’s granted funnyness notwithstanding:
I don’t believe the family name “Drumpf” has ever existed in Germany. “Trumpf” is still around, which translates to “Trump” in English. I checked the white pages of all the major German cities. Not a single listing for “Drumpf” in any of them. There were numerous “Trumpf”s. And the last name of a friend of mine is “Trumpa”…wherever that came from. Doesn’t mean anything, just like “Drumpf”.
In the historical German handwriting, Kurrent, that was current from the 18th to the late 19th century, the upper case “T”, in sloppy writing, might well be mistaken for a “D”. See example here: