WASHINGTON — U.S. Sen. Mazie Hirono filed a lawsuit Monday seeking to block Matthew Whitaker from serving as acting attorney general.

Hirono joined two of her Democratic colleagues, Sens. Richard Blumenthal and Sheldon Whitehouse, in the legal action, saying that Whitaker’s appointment by President Donald Trump was unconstitutional.

Nick Grube/Civil Beat

Specifically, the senators argued Whitaker’s assignment as the nation’s top law enforcement official was a violation of the Appointments Clause, which says that a president’s nominations are subject to the “advice and consent” of the U.S. Senate.

That means Whitaker, like his previous boss Jeff Sessions, who was forced to resign, should be subject to a confirmation hearing before the Senate Judiciary Committee. Hirono, Blumenthal and Whitehouse are all members of that body, which they argued gives them standing in the case.

.@SenBlumenthal, @SenWhitehouse, and I just filed suit to challenge @realDonaldTrump‘s unconstitutional appointment of Matthew Whitaker as Acting Attorney General. Donald Trump cannot subvert the Constitution to protect himself and evade accountability. — Senator Mazie Hirono (@maziehirono) November 19, 2018

Without exception for President Trump’s allies, principal officers who report directly to the President must be subject to a hearing and confirmed by the Senate. — Senator Mazie Hirono (@maziehirono) November 19, 2018

Among the senators’ concerns is that Whitaker is a Trump loyalist who could threaten to end Special Counsel Robert Mueller’s ongoing investigation into whether the president, his family and closer advisors worked with Russians to help sway the 2016 election.

There are also concerns that Whitaker, a former U.S. attorney, will be the subject of an ongoing FBI investigation involving a patent company accused of bilking customers out of millions of dollars.

According to the lawsuit, Whitaker was on an advisory board for the company during the time of the alleged misconduct, which ultimately resulted more than $25 million in penalties. The FBI is now conducting a criminal investigation into the company’s actions.

Read the senators’ lawsuit here: