Top Democrat says Trump firing of Mueller could provoke 'constitutional crisis'

WASHINGTON (Reuters) - The top Democrat on the U.S. Senate Intelligence committee, responding to escalating Republican attacks on Special Counsel Robert Mueller, said on Wednesday that if President Donald Trump fires Mueller, "it has the potential to provoke a constitutional crisis."

Senator Mark Warner, speaking on the Senate floor, denounced attacks on Mueller's impartiality, and said the special counsel's investigation of ties between Trump's presidential campaign and Russia must be "able to go on unimpeded."
While Trump's political allies have increased their criticism of Mueller, the president said on Sunday he was not considering firing him.

(Reporting by Warren Strobel and Jonathan Landay. Editing by Jonathan Oatis)