It is quite a moment in American history when the White House issues a public service announcement to point out that the nation’s president is still at the helm.

“PSA: TRUMP IS STILL YOUR PRESIDENT,” read a post on White House social media accounts after the Republicans’ midterm drubbing. The message was emblazoned over a close-up photograph of a stony-faced Donald Trump with his fists firmly planted on the Resolute Desk in the Oval Office. 

How much actual power remains in those fists is open to question, at a moment when triumphant Democrats all over the country are celebrating a historic victory and preparing to descend on Washington in January to take control of both houses of Congress. 

It is easy to brand Trump a “lame duck”, and in the classic sense of that phrase, he will suddenly become one on 3 January when the new Congress is sworn in. From that day forward, the President is unlikely to get any of his favoured legislation passed by Congress.

But Trump is not measured by normal historic custom and practice. Having had precious little use for Congress, he chooses to govern by issuing executive orders. Invariably, those diktats are of dubious legal provenance and can be challenged, but this president prefers to fight his battle in the courts rather than in the corridors of power.

His so-called “Liberation Day” tariffs, for instance, tumbled from the White House without any reference to Congress. The Supreme Court later eviscerated them but – faced with a choice of working to implement tariffs via the legislative branch or simply finding a rationale for targeting nations overseas with punitive customs duties – he chose the latter course. He is not likely overnight to have become a man interested in adhering to constitutional strictures.

Past American presidents who have suffered midterm election blows have chosen to focus on areas where they retained broadly defined powers. Foreign policy, for instance, is often the retreat of a politically battered US leader, and Trump may seek to remain the dominant force in steering America’s activities on the world stage. 

While Democrats are sure to pass bills denying Trump any permission to wage further war on Iran, Trump is sure to ignore them. He already argues that his battle with Iran is a “military operation”, not a war, and therefore bypasses the War Powers Act that is designed to give Congress a role in any hostilities a president wants to ignite.

Some believe that, now the political damage is done, Trump may be less restrained on Iran and launch massive strikes on the country’s infrastructure. Or he may decide to carry out a hit on Iran’s Pickaxe Mountain, which is linked to its nuclear programme. He could then argue he had done enough to damage Iran’s nuclear ambitions while leaving the door open to an elusive agreement to reopen the Strait of Hormuz.

Cuba remains unfinished business for Trump, with the President previously claiming he expects to enjoy “the honour” of seizing control of the island. He referred earlier this week to his “conquest” of Venezuela – the first time he has used that phrase. The communist authorities in Havana, hoping to run out the clock on the Trump administration, may not have the luxury of time on their side, given the President’s sudden need for quick wins.

But in other areas of international policy, Trump may find himself suddenly constrained. Prime Minister Andy Burnham indicated on Wednesday fresh determination on the part of European leaders to challenge Trump over the damage the Iran war has done to their economies. The G20 Summit that Trump will chair at his Florida golf club in December may be more confrontational given his election drubbing.

Constitutionally, tariffs are the unique preserve of Congress. Trump and his fellow Republicans in Congress spent the past two years conspiring to ignore those arrangements, but Democrats will seek to close whatever loopholes they can in a bid to restore the legislature’s role in tariff enforcement. Some prominent Republicans are already demanding a dilution of tariffs to ease the inflationary pressures they have created at home, and return their party to its free trade roots.

Democrats will need to decide how to use the investigative powers they will soon enjoy. “Lawyer Up” was the advice given to Trump administration members on Tuesday night by Robert Garcia, the Democratic Congressman soon expected to head the House Oversight Committee. For Defence Secretary Pete Hegseth, Attorney General Todd Blanche, Health and Human Services Secretary Robert F. Kennedy Jr and many others, life is sure to become a miserable cycle of legal probes and combustible hearings on Capitol Hill. 

Trump denied any concerns about his possible impeachment, telling reporters on Wednesday that “it would destroy the Democratic Party if they did that”. But investigations of his wealth and his family’s connections could prove intrusive.

After the 2018 midterms, the first Trump administration routinely ignored subpoenas, refused to send people to testify at hearings and failed to provide requested documents. There is every chance Trump will use the same delaying tactics to thwart any future investigations, forcing Democrats to hold members of his team in contempt of Congress for any failure to co-operate.

The next few weeks could see Trump move to shore up his damaged position. The “lame duck” session of Congress from now until the end of the year will provide the Republican majorities in the House and Senate a final chance to pass legislation that may protect the priorities of Trump’s Make America Great Again movement. 

That could mean another fast-tracked “reconciliation bill” to advance Trump’s priorities, which could include a debt limit increase, war funding, voting restrictions, a crypto strategy and new policy on hemp-derived products.

Government funding is due to expire on 11 December, and before the midterm elections, Republican Senator Bernie Moreno of Ohio told reporters he anticipated a “Last Supper” effort by Republicans to cement their priorities during the lame duck session. But whether Trump’s bruised lawmakers will be sufficiently disciplined to do the President’s bidding is now in doubt.

Another institution to watch is the US Supreme Court. Justice Clarence Thomas, 78, and Justice Samuel Alito, 76, have both been rumoured in recent months to be considering retirement. Were either of them to seek a quieter life, there would be no better time for it than now.  

By the time January rolls around, Trump stands no chance of securing congressional backing for any Supreme Court nominee that might be acceptable to Republicans. Governor Ron DeSantis of Florida might be a tempting choice, not least because he is already giving voice to a possible presidential run in 2028 that could turn him into a powerful Trump critic outside the President’s inner circle.

Alito and Thomas, reliable and loyal conservatives, must act now or hold their peace for at least two more years. On Wednesday night, reported that Alito has told friends he has no immediate plans to hand in his notice.

Trump must also now contend with the succession battle already beginning within Republican circles, as Vice President JD Vance, Secretary of State Marco Rubio and others seek to position themselves for the 2028 presidential contest. That, too, may sap his powers, with Vance and Rubio more likely to try and constrain the octogenarian President’s actions than before in order to create distance from him and his deeply unpopular record in office. 

Trump could soon become very lonely in the White House. A president who thrives on attention may find it directed beyond him.