Cooperation is a thing of beauty when it works, and it's working here.

Pennsylvania Attorney General Josh Shapiro and Washington DC Attorney General Karl Racine filed an amicus brief today on behalf of 15 state attorney generals seeking an injunction to block the appointment of Matthew G. Whitaker as acting U.S. attorney general.

The amicus brief supports the original suit filed two weeks ago by Maryland Attorney General Brian Frosh which highlighted that President Donald Trump’s appointment of Whitaker is against the Appointments Clause of the Constitution, which mandates that “principal” senior officials, such as the attorney general, be confirmed by the Senate.

Maryland's suit also pointed out that Whitaker’s appointment violates a specific federal law that details the line of succession and automatically gives the acting role to the deputy attorney general when the attorney general position is vacated.

In announcing the brief, Pennsylvania's attorney general highlighted the importance of the action saying that, “The naming of Matthew Whitaker as Acting Attorney General is unlawful, and his appointment threatens the legitimacy of the Department’s actions and its vital relationship with the States.”

Shapiro also added, “I’ve filed in court to protect Pennsylvania’s interests and immediately prevent actions of an illegitimate Attorney General whose decisions could be invalidated.”

With Whitaker already in place as acting attorney general, it remains to be seen how quickly the courts can and will move to rule in seeking his removal.

With the fate of the Mueller investigation hanging in the balance, Whittaker's removal looks to be essential to preserving the rule of law and the transparency of the Trump administration.  If the courts are slow to move, however, we very well could see Whittaker pulling the rug from under Mueller and completely shutting down the investigation.  We're sure nothing would please Trump more.

The other states joining Pennsylvania and the District of Columbia in the amicus brief are Connecticut, Delaware, Hawaii, Illinois, Maine, Massachusetts, New Mexico, New York, North Carolina, Oregon, Rhode Island, Virginia, and Washington.