Federal Election Commission filings show that four members of Mueller's team, including Michael Dreeben, Jeannie Rhee, Andrew Weissmann and James Quarles, have made substantial donations to Democratic candidates or the Democratic Party over the past several decades.
Dreeben, a deputy solicitor general for the US Justice Department, donated $1,000 to a political action committee for then-New York Senator Hillary Clinton, while he was a deputy solicitor general.
Rhee donated $5,400 to Clinton's presidential campaign, and Weissmann donated some $4,700 to Democratic organizations supporting the election of former President Barack Obama.
Quarles has made monetary donations to Democratic candidates going back to the 1980s, according to the Federal Election Commission.
Retired Republican lawmaker Newt Gingrich observed that it is unlikely, given these revelations, that Mueller's team will be impartial and unbiased.
— Newt Gingrich (@newtgingrich) June 12, 2017
As investigations press on into alleged ties between Trump's team and Moscow, no evidence of the Kremlin's alleged influence on the election has been provided so far.
Russian officials have repeatedly denied charges of interfering in the vote, saying the allegations are absurd and represent an attempt to divert the US public's attention from revealed instances of corruption as well as other pressing domestic issues.