In the 2016 presidential race, Jeff Sessions along with Gov. Chris Christie were critical early supporters of then candidate Trump's seemingly improbable campaign. Christie was quickly tossed aside in the furor over the George Washington Bridge closings while Sessions went on to claim one of the new president's most important cabinet posts, attorney general. Now Sessions, it appears, is in the political dock.

White House insiders say discussions are underway about the possibility of firing Sessions because of special counsel Robert Mueller's Russia probe, and Trump, rather than quieting speculation has been fanning the flames with taunts about "our beleaguered AG." Sessions, a former U.S. senator from Alabama, has strong support among conservatives, including radio talk show host Rush Limbaugh, and the likelihood is that a decision, if taken, will bear Trump's signature style of acting on instinct.

If Sessions is shown the door here are five things to watch for:

• A political uproar of course, but not just among Democrats, who will call for impeachment, and neo-conservative Never Trumpers. Many middle of the road Republicans will wring their hands and voice outrage. Firing the attorney general will once again awaken memories of Watergate, when then president Richard Nixon fired special prosecutor Archibald Cox, a decision that only seemed to underscore Nixon's guilt and resulted in the resignation of his own attorney general.

• By the time Nixon fired Cox, there was as well-developed criminal case implicating the president and most of his supporters had made for the exits. Not so with Trump. His support among his base remains strong and so does the belief that the media, acting out of its own loathing of Trump, its politics and cultural biases being so unlike those of Trump, is attempting to orchestrate his demise. That as yet no evidence has emerged showing the campaign conspired with Russian operatives to subvert the 2016 election will only intensify this reaction.

• Any move to replace Sessions surely will be part of a larger effort to rein in independent counsel Mueller, if not get rid of him altogether. Despite promises to the contrary, Mueller's investigation has been leaking like a rusty oil tanker, and Trump seems to believe he's being tried in the press. That Mueller's prosecutorial team includes Hillary Clinton donors, or that Mueller is close friends with fired FBI Director James Comey, whose own leak set the stage for Mueller's appointment, has only intensified the sense among Trump insiders that the deck is stacked.

>> Read more: What's Robert Mueller supposed to do as special counsel?

• Financial markets could take a huge, likely momentary, hit if Sessions and or Mueller are fired, accentuating the sense that Washington politics have run off the rails and that a new era of extreme uncertainty has begun.

• Trump would appoint a trusted loyalist to replace Sessions, like former New York Mayor and U.S. Attorney Rudolph Giuliani, or a staunch conservative, like U.S. Sen. Ted Cruz of Texas, but the nominee would likely face a tough Senate confirmation fight. The Russia probe would continue, but likely within very constrained boundaries. The Trump business empire, which according to some recent reports, now is in Mueller's cross hairs, could end up strictly off limits.