Trump still has two weeks left -- but how much of a future?

Abandoned in the White House by former allies, a deeply isolated Donald Trump has two weeks left to contemplate the rubble of his presidency -- and perhaps his dreams of a return in 2024.

Trump repeatedly tested the limits of what a US president can get away with. He gleefully broke every norm, survived impeachment, and saw off Special Counsel Robert Mueller's explosive probe into his contacts with Russia.

But Wednesday's debacle, in which Trump encouraged a mob storming Congress trying to certify Democrat Joe Biden's election victory, was beyond the pale even for Republicans.

For years, party leaders like senators Mitch McConnell and Lindsey Graham had performed contortions to avoid confronting the populist president.

No longer.

"Enough's enough," Graham pronounced in Congress after lawmakers reconvened into the early hours of Thursday to complete Biden's certification.

Around them lay the debris of Trump's darkest day -- trashed offices, broken windows and bullet holes from shootings that left one woman dead.

"It's over," Graham said.

- Isolated -

From his ever more lonely perch in the White House, Trump is left to watch Washington turn on him and to wonder if his once near mythical political powers can be saved.

While Republicans now dare to despise Trump openly, Democrats are going further, encouraging government officials to invoke the 25th Amendment declaring a president no longer capable of performing his duties.

"This president should not hold office one day longer," Senator Chuck Schumer, set to lead the Senate when a new Democratic majority takes office, said Thursday.

Calling on Vice President Mike Pence to invoke the 25th and eject Trump immediately, Schumer said the alternative would be for Congress to "reconvene to impeach the president."

Trump, long used to being humored and flattered by his ever-changing cast of White House aides, will now find fewer ready to stay by his side.

On Thursday, Trump insider Mick Mulvaney was the latest to quit and indicated that a trickle of other departures may become a flood.

"I can't stay here, not after yesterday," Mulvaney, who served as Trump's chief of staff before moving to Northern Ireland envoy, told CNBC television.

According to Mulvaney, only fear of what might still happen in the dwindling days before Biden's inauguration on January 20 holds other senior figures back.

"Those who choose to stay, and I have talked with some of them, are choosing to stay because they're worried the president might put someone worse in," he said.

Already on Wednesday, deputy national security advisor Matt Pottinger resigned, followed by First Lady Melania Trump's spokeswoman Stephanie Grisham.

Trump himself remained silent early Thursday, hamstrung by the unprecedented decision by Twitter and Facebook -- the two giant platforms essential to Trump's rise -- to block him.

- What's next? -

Until January 20, Trump still retains control over everything from the nuclear missile codes to the red button on the Oval Office desk that summons a butler to deliver his beloved Diet Cokes.

That lag raises potential for more turmoil in the next two weeks, as Trump ponders how to secure his longterm future.

As he has made clear since losing the November election, Trump literally cannot believe that he shouldn't stay in the White House.

And if he can't stay, he has repeatedly toyed with coming back on an epic revenge campaign in 2024.

The mere prospect of Trump 2.0 has cowed other Republican would-be presidents. Trump, always the loudest voice in the room, is all but assured to be the party's frontrunner.

His self-promoted brand as a natural political genius has taken a hit in the last few days.

Quite apart from the mayhem on Wednesday, there's the embarrassing fact that Trump's personal campaigning failed to prevent the two Republican Senate candidates from losing in Georgia, thereby handing Democrats control of Congress.

But in the burn-it-all-down mentality of team Trump, none of this necessarily matters.

"This isn't their Republican Party anymore. This is Donald Trump's Republican party," his son Don Trump Jr told the president's angry crowd on Wednesday.

As ever, it's his base -- passionate, well organized, aggrieved and prone to conspiracy theories -- that the president believes is key to keeping his ship afloat.

He may not be wrong.

According to an Axios-SurveyMonkey poll this week, 62 percent of Republicans still don't accept that Biden won in November.

"Let the weak ones get out," Trump intoned Wednesday in his speech whipping up the crowd. "This is a time for strength."