MSNBC host Joe Scarborough tore into former House Speaker Newt Gingrich (R-Ga.) on Thursday after he attacked special counsel Robert Mueller as a dubious investigator bent on attacking President Trump.

In a stream of tweets, Scarborough accused Gingrich of "sliming an American hero" and fanning anti-government conspiracy theories by floating the notion that Mueller is a part of the so-called deep state.

Gingrich's trashing of Mueller early Thursday morning followed a Washington Post report that the former FBI director, who is charged with leading the law enforcement investigation into Russia's role in the 2016 presidential election, was expanding his probe to include possible obstruction of justice by Trump.

In his postings, Gingrich accused Mueller of running his investigation with the intent of "destroying or at a minimum undermining and crippling the Trump presidency."

Trump himself appeared to smear Mueller and the investigation on Thursday, writing in his own tweet that the probe was being "led by some very bad and conflicted people!"

In fact, Mueller has been widely praised by both Democrats and Republicans, who view him as an impartial and reliable law enforcement official and investigator. He was appointed as special counsel to lead the Russia probe last month after Trump abruptly fired FBI Director James Comey.