(CNN) President Donald Trump's sudden dismissal of Attorney General Jeff Sessions was a swift strike to exploit Washington's new power dynamics after the midterm elections.

It represents a huge risk since Trump's ultimate aim seems to be to endanger special counsel Robert Mueller's Russia probe, and the move is almost certain to lead to an immediate investigation once the new Democratic House majority gathers in January.

In a way, Wednesday was peak Trump, with the President making a transparent effort to change the narrative after the GOP's monopoly on Washington power crumbled on Tuesday.

But the grave implications of ousting Sessions mean it adds up to much more than a normal Trump head fake to drown out a damaging headline.

His canning of the former Alabama senator and the widened Republican Senate majority mean he can install whoever he likes at the Justice Department -- giving him effective control over the investigation into his own campaign's actions.

With a single swipe, he rid himself of an attorney general who had recused himself from the Russia probe. Trump had been tormenting Sessions on Twitter for months.

He immediately replaced him with an acting attorney general, Matthew Whitaker, who is on record, including in an outspoken CNN opinion piece , expressing fierce opposition to the Russia investigation.

"It's a break the glass moment," Democratic Sen. Richard Blumenthal of Connecticut told CNN's Kate Bolduan on Wednesday night.

"Our democracy is under attack. It's a kind of a slow-motion 'Saturday Night Massacre,' as occurred under President Nixon."

Whitaker, who served Sessions at the Justice Department as his chief of staff, now has the power to oversee Mueller, who is seen as moving toward the end of his investigation. Whitaker could narrow the range of the special counsel's mandate or limit funds for his work. It's possible he could also control whether any final report is made public. And he could lay the groundwork to dismiss Mueller.

Whitaker's elevation also wrested control of the Russia probe away from Deputy Attorney General Rod Rosenstein, who has shielded Mueller, and is viewed in Washington as a nonpolitical career official acting with integrity.

Changing the subject

It's not Trump's style to admit mistakes. So he turned the traditional grim post-midterms presidential news conference into a sideshow while waging a base-pleasing war on the press with a fulminating display at a post-election news conference.

Not for Trump the gloom and self-recrimination of Presidents George W. Bush and Barack Obama when they bemoaned a midterm "thumpin' " and a "shellacking." Rather than express guilt about lawmakers who lost their jobs, Trump openly bid good riddance to Republicans who had spurned his "embrace."

"Mia Love gave me no love, and she lost. Too bad. Sorry about that, Mia," Trump said, of a Utah lawmaker whose race is yet to be called.

Following a playbook that had helped him quickly forget business failures in his previous life, he simply declared victory -- hailing an increased GOP majority in the Senate as an "incredible day" that he had been instrumental in building -- and moved on.

It's not unusual for Cabinet officials to pay the price for their boss's failure at the polls. There was an ironic precedent to the toppling of Sessions. Twelve years ago, as Speaker-elect Nancy Pelosi was setting the terms for a new political alignment after winning the House -- just as she was Wednesday -- Bush forced out his defense secretary, Donald Rumsfeld.

The President has every right to dismiss any of his Cabinet officials. But his open denunciations of the Mueller probe and months of attacks on the special counsel mean that Trump's critics are deeply skeptical of his motives.

Dangerous ground for Mueller

The swift succession of events appeared to leave Mueller on dangerous new ground.

"You can't sound too many alarm bells about what has been going on," Preet Bharara, former US attorney for the Southern District of New York, said on CNN's "The Situation Room."

From the outside, Trump's move against Sessions looked very much like the latest in a sequence of steps, starting with the firing of FBI chief James Comey last year, to undermine the Russia investigation.

With that in mind, some legal experts questioned whether the backstory of what happened could eventually be perceived as more evidence of corrupt intent, which would be needed to support any finding by Mueller that the President had obstructed justice.

Trump has repeatedly demanded loyalty and protection from his subordinates and Whitaker may soon begin to feel the same kind of heat.

The President's move presented an immediate challenge to Pelosi, who he had praised earlier Wednesday for her likely return to the speaker's chair, and offered to open a new era of deal making between Washington power players.

She said it was impossible to see the firing of Sessions as "anything other than another blatant attempt" to undermine and end the Mueller investigation.

But as she also called for Whitaker to recuse himself, Pelosi knows, just like Trump, that there are two months before Democrats have the means to check the President's power.

It could be that Trump is calculating that he has a window to do as much as he possibly can to stifle Mueller's room to maneuver, under the cover of the sympathetic outgoing Republican-led House and the GOP Senate.

"The moment of precariousness is, I think, especially significant now because we are in the lame duck phase," said Bharara.

"You have an opportunity to do something very damaging to that investigation."

Trump may also have been emboldened by the replenishment of his power offered by strong support from his political base, which turned out in droves to push his acolytes over the line in key Senate races in red states.

And his task of confirming a new attorney general becomes even easier in a Senate that has more Republicans and is even more in his debt.

Trump was not content Wednesday with casting a new cloud over Mueller.

He threatened openly to weaponize one part of the federal government, the Republican-led Senate, against another, the new House that takes office next year, if the pain of oversight becomes too acute.

"They can play that game, but we can play it better," Trump said at his news conference.

Such a move would surely amount to an abuse of presidential authority in the unlikely event that Republican Senate Majority Leader Mitch McConnell, a student of the separation of powers, would go along.

Still, the President's comment represented a warning that he would try to strong-arm the newly Trumpian Senate into following his will, much as he did to parts of the Republican-led House, including the Intelligence Committee.

It is far from the first time Trump has vowed to wield presidential power to further his political goals. On the campaign trail he vowed to wipe out the constitutionally guaranteed birthright citizenship with an executive order.

And using his powers as commander in chief, Trump sent thousands of troops to the southern border to meet a yet to emerge threat from a migrant caravan that was at the center of his searing campaign message.

But if his move against Sessions, was, as it appears, meant to hike pressure on Mueller, it could just as easily backfire since it seems almost certain the new Democratic-led Judiciary Committee will look into the dismissal early in its tenure.