The stand-off with the Democrats over his Wall project is just one of many major challenges in the new year
Donald Trump enters 2019 locked in a fierce political battle with new House Speaker Nancy Pelosi, a fight he will lose.
He cannot force Democrats to apportion money for a wall between the United States and Mexico, but influential conservatives in media threaten to punish him if he retreats. He will eventually find a way to surrender while declaring victory. And then his year will become even more complicated.
Mr Trump's 2019 "to-do" list is formidable, even by presidential standards. He must help restore confidence in the US economy after three months of the worst US stock market meltdown in many years, and he must accomplish this at a time when global economic growth is beginning to look soft.
He must reassure the world that the United States and China are not on a course towards endless trade conflict or a Cold War-scale military confrontation while addressing the genuine security concerns of those who believe China continues to take advantage of the United States, its companies, and its workers. He will need to show real progress towards denuclearisation of the Korean Peninsula by persuading North Korean leader Kim Jong Un that he cannot get something for nothing.
He must persuade critics that the vague promises made last year in Singapore hold promise without allowing Mr Kim to continue with clandestine nuclear development.
He needs to deliver the promised withdrawal of US troops from Syria without appearing to cede power and influence in the Middle East to Russia and Iran - and without leaving Kurds and other allies at the mercy of Turkey President Recep Tayyip Erdogan and his military.
More importantly, he must execute this retreat without losing whatever confidence the US Defence Department still has in his leadership. He must begin to prepare for re-election. With low approval ratings, growing doubts among his core supporters, and after a loss of historic scale in November's midterm elections, he must discourage any Republican from challenging him for the party's nomination, and he must find a way to break the momentum that Democrats now enjoy.
The obstacles he faces are daunting. China's President Xi Jinping cannot be seen to buckle under Mr Trump's pressure, and China's political and economic system gives the Chinese leader formidable weapons with which to limit damage to China's economy.
Russia's Vladimir Putin can treat Mr Trump as a compromised figure and Europeans who have long called for less reliance on US protections now have the best case for their plans they have ever had. The cost of partnership with Mr Trump is rising for leaders of countries who can afford to ignore him, and an "America First" foreign policy driven by a capricious personality makes the benefits less clear.
Then there are the domestic challenges. Mr Trump was elected in part because he had no experience in government. In that sense, he was the embodiment of change.
The downside for him is that he is still unsure how government actually works. Not so for Ms Nancy Pelosi, who is as experienced, savvy, and ruthless an adversary as the President could expect to face.
The party Ms Pelosi leads now has real power for the first time since Mr Trump was elected President, and Democrats intend to use that power to subject him to a level of scrutiny Mr Trump has never experienced.
They will subpoena both documents and members of his administration to testify under oath on any number of sensitive subjects, and Mr Trump's patience, poise, and self-confidence will be tested as never before.
The greatest risk for Mr Trump is that Republicans - voters and lawmakers - decide they can no longer afford his leadership. The daily "outrages" reported by the press and repeated by incredulous Democrats would not sway his most loyal supporters or their elected representatives. But if he comes to be seen as a loser - because foreign leaders are ignoring him, Democrats are thwarting his plans, the economy is turning, and especially if polls begin to signal he cannot win - there is a risk they will abandon him.
Then there is special counsel Robert Mueller, who will continue to lead investigations into nearly every aspect of Mr Trump's public life - his business history, his personal indiscretions, his presidential campaign, his White House, his associates and even his family.
Whether weeks or months away, the report of his findings will shake Washington like nothing we have seen in at least a generation.
The greatest risk for Mr Trump is that Republicans - voters and lawmakers - decide they can no longer afford his leadership.
The daily "outrages" reported by the press and repeated by incredulous Democrats would not sway his most loyal supporters or their elected representatives. But if he comes to be seen as a loser - because foreign leaders are ignoring him, Democrats are thwarting his plans, the economy is turning, and especially if polls begin to signal he cannot win - there is a risk they will abandon him. We are still some distance from that point. Those who underestimate Mr Trump's political instincts are making a mistake.
There have been few figures in American public life who better understand the sources of fear and anger that drive his most reliable followers, and Democrats may well nominate a presidential candidate that pushes Republicans back towards Mr Trump, whatever their misgivings. But 2019 is sure to be the most challenging year of Donald Trump's life.
•Ian Bremmer is the president of Eurasia Group and author of Us Vs. Them: The Failure Of Globalism.
A version of this article appeared in the print edition of The Straits Times on January 07, 2019, with the headline 'Rocky road ahead for US President'. Print Edition | Subscribe
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