A study released Thursday found that 90 percent of political donations by Google, YouTube, and other subsidiaries of Alphabet have gone to Democrats.

In 2016, when Donald Trump defeated Hillary Clinton, Alphabet employees donated more than $5.8 million to Democratic candidates and causes, while only $403,042 was contributed to Republicans. Ninety-four percent of Alphabet contributions in that year went to Democrats.

[Opinion: Google News is heavily biased – but it's not rigged]

From 2004 to 2017, $15 million donated by employees of Google and its related companies went to Democrats, and just $1.6 million went to Republicans. Alphabet was created in 2015 as an umbrella company for these companies.

The GovPredict study was released as Republican pressure has increased on these companies to explain whether Google's search algorithm is designed to hide conservative news or opinion.

Of the Republicans polled in an Axios survey on the public’s trust in technology, 67 percent said they believe Internet search engines are programmed to produce results that are biased to favor a liberal point of view. PJ Media found last month that 96 percent of Google search results for “Trump” turned up hits from left-leaning or liberal outlets such as CNN, the Washington Post, and NBC.

Although Republicans feel the bias from search engines, almost half of poll respondents, 46 percent, said they did not think the sites had bias at all.