They actually don’t do it that way. They do it by changing what you’re searching for, without you knowing it. For example, you search on “Trump”, they change it to “Trump is an idiot” and then let search do their job. That way nothing can leak through. Again, all done in background, you never know it.
IIRC They did the same with Bush and failure.
I can search for photos and videos and articles that I know exist but unless I triangulate my searches (specifying a specific website for example, including youtube) I won’t get a match.
And there has been a lot of scrubbing of Obama and Clinton photos from image searches.
But then the images search capabilities went down 5 years ago when searching for The Beatles might reveal a photo of the Rolling Stones within the top 30 matches. Contemporaries/rivals yes but not the same and not requested. This is not so common with this specific subject now but provided as an example.