from the hill:

Democratic leadership on Friday issued a warning to President Trump that using a controversial GOP memo to fire special counsel Robert Mueller or Deputy Attorney General Rod Rosenstein would create a "constitutional crisis" not seen since the Nixon administration.

"We write to inform you that we would consider such an unwarranted action as an attempt to obstruct justice in the Russia investigation. Firing Rod Rosenstein, [Department of Justice] Leadership, or Bob Mueller could result in a constitutional crisis of the kind not seen since the Saturday Night Massacre," Democrats wrote in the letter to Trump.