Leading up to the 2020 election, right-wing media outlets started claiming that their sites were being heavily shadow banned in Google search. Breitbart, for example, reported the following in July of 2020:
New data shows that Google has suppressed Breitbart’s search visibility by 99.7 percent since 2016.
On April 4, 2016, Breitbart ranked in the top ten search positions (i.e., on the first page of Google search results) for 355 key search terms; but now, as of July 20, 2020, Breitbart ranks in the top ten search positions for only one search term. And, on April 4, 2016, Breitbart ranked in the top 100 search positions for 16,820 key search terms; but now, as of July 20, 2020, Breitbart ranks in the top 100 search positions for only 55 search terms.
Moreover, organic Google search traffic to Breitbart (measured by unique visitors) is down 63 percent when comparing the first half of 2016 with the first half of 2020.
Other right-wing / conservative media outlets such as The Daily Caller reported similar things happening around the same time. A few months later, on September 20, 2020, RealClearPolitics confirmed these claims in a very thorough report titled Google Pushes Conservative News Sites Far Down Search Lists:
It has long been feared that Google, which controls almost 90% of U.S. Internet search traffic, could sway an election by altering the search results it shows users. New data indicate that may be happening, as conservative news sites including Breitbart, the Daily Caller, and the Federalist have seen their Google search listings dramatically reduced.
About a month later, this was still happening, as Breitbart reported that a news article wouldn’t even appear in the Google search results even if searched for by the precise title of the article itself:
It appears that Breitbart News links are being hidden on Google searches even when users search for the exact string of words in an original Breitbart headline. When links to Breitbart stories do appear, it is often below obscure websites that plagiarize Breitbart’s content.