“We estimate, based on win margins in national elections around the world, that Google could determine the outcome of upwards of 25 percent of all national elections.” (Robert Epstein). Or, as WIRED puts it, "Google's ranking algorithm for search results could accidentally steal the presidency". "Accidentally" may not be the case since Google has its finger on the scales a little bit to damp down climate change deniers and such.
I'm glancing at the margins of my open web pages and note that Google is advertising to me a trip to Iceland, shirts to order on line, compact dishwashers, and a hotel on Galliano Island. Google's got me in an echo chamber with ads tailored to me and Google wants to tailor the answer to my questions about the world too. You know they cannot resist tweaking things a teentsy bit to improve my outlook. It's the same reason governments always print a little extra money because a little inflation is good for the system and it's so easy to put the extra in their own account first.