I disagree with Rick's answer. In particular
The role of influencers is to "promote or discredit political causes ...", a close reason.
Every politician does the same thing, promotes or discredits something. So by that logic, question about politicians would be off-topic too.
That close reason applies to questions themselves, not to whether indirectly the topic of the question is about someone who does such things for a living.
As for the actual question at hand here, it's more debatable. See my previous question about Fox News personalities. By far the top-voted answere there (by agc) was:
Popular pundits should be considered as political opinion journalism. Its value as a topic here would be in proportion to what's said is:
verifiable. Pundit asserts that a candidate is secretly a lizard-man, because of evidence X,Y, and Z. Questions about X,Y, and Z should be OK, even though we're skeptical that lizard-men exist.
measurable. Pundit usually screams with rage whenever a certain politician's name is mentioned, but coos with pleasure when a rival is named. Questions about the average decibel contrast between respective screams and coos should be allowed.
acted upon. Pundit promotes anti-lizard-man bill, which becomes law due to Pundit's popularity. Questions about implementation, costs, and effects of said law should be allowed.
You can easily apply that reasoning to influencers who might not be (self-styled) pundits.
I thinks what was left unsaid in that answer, and so what some (perhaps most) would consider off-topic are questions about the media careers of the pundits/influencers themselves. E.g. some sex scandal about a politician is usually on-topic. The same kind of scandal about a CNN or Fox News anchor/pundit is perhaps not on-topic here.
Likewise, we have a tag about political theory here, and such questions are on-topic, even if they sometime involve ideas or works of political scientists rather than those of politicians. But the academic careers of political scientists are probably off topic (and I can't remember anyone even wanting to ask a question like that here.)