Believe it or not, but there are also people from outside the USA roaming the internet. They're usually way more out of touch when it comes to US American politics, and only know the very few biggest players. You can expect a foreigner (who's not entirely politics ignorant) to know who the president of the US is. That is basic, surface level knowledge. But even important people like the vice president, are far less relevant for people not living in the US.

You most likely also don't know about the intricacies of the political systems of other countries. nor their sub-surface people doing their job and contributing to the system. These people are relevant and sometimes important to anyone living there.

So, why the hell should they be expected to know who some employee/hired person for a US president was?

...that aside, mocking someone for something they don't know is just childish and counter productive. If you already put in the energy, why not use the energy to educate, instead of trying to make them feel bad?