President Donald Trump tweeted a conspiracy theory promoted by right-wing non-profit Judicial Watch that says that Google manipulated up to 16 million votes for Hillary Clinton through its search algorithm.

"Wow, report just out! Google manipulated from 2.6 million to 16 million voters for Hillary Clinton in the 2016 election! This was put out by a Clinton supporter, not a Trump supporter! Google should be sued. My victory was even bigger than thought!" Trump tweeted Monday afternoon.

Psychologist and journalist Robert Epstein has claimed in 2016 that Google search algorithms skew search results to the left, calling his theory the "Search Engine Manipulation Effect." Conservative media outlets have heavily promoted the theory, while Google says the idea is a "poorly constructed conspiracy theory."

A Google spokesman said that "our goal is to always provide people with access to high-quality, relevant information for their queries, without regard to political viewpoint."

The 2016 popular vote tally is a sore spot for Trump, as Clinton won the popular vote by almost 3 million. Trump still won the electoral college, which allowed him to win the presidency.

Trump has said that voters in California illegally voted multiple times in the 2016 presidential election while speaking to conservative youth organization Turning Point USA in July.

The New York University's Brennan Centre For Justice has said that voter fraud is "very rare" and that "much of the problems with alleged fraud relate to unintentional mistakes by voter or election administrators."

In addition to alleged voter manipulation, conservatives such as Sen. Ted Cruz of Texas have claimed that Google censors right-wing speech and that Google should undergo a third-party, independent audit to discern whether the search engine has biased results.