I just searched for those words, and I saw all of the candidates.
Google will adjust search results based on your previous searches and your previous selection of search results. So, if you have been searching a lot of opposition candidates recently, and then you do a search of “presidential candidates”, your results might be skewed as compared to my results.
I have seen cases in the past where I do the same search at work vs. at home, and the results are different. That’s because the information I look for at work is not the same information I need at home.
Strange. I just see the three. Trump’s not there. Seen screenshots from other people with the same result. I tested it prior to posting.
Although search history does effect your Google results, especially if you do not clear your browser history, Google should still list all of the candidates when you search for “candidates for president” or “presidential candidates.”
I have never searched for Hillary, Bernie, or Jill and you can see the results that I got above in my post with the screen shot. Trump is left out intentionally.