Donald J. Trump is a very stubborn man. It was likely this mulishness as a child that caused his parents to ship him off to military school for discipline. Yes, at military school, he acquired discipline but he was still obstinate ... because it served hm well there. He left the New York Military Acadamy as its top officer.
Then, against his father's advice, he went into the construction business in Manhattan, the toughest venue for builders. I suspect that again his bullheadedness also served him well ... along with his deal making and attention to detail. I also suspect most of his opponents eventually gave in to his stubbornness and let him have his way. This led to fame, wealth, two divorces and, eventually, the presidency.
Now, as president, Trump is exhibiting much more spine than most of his predecessors. He has run into other mules who imagine that they are his parents ... John McCain, Jim Comey, Nancy Pelosi, Chuck Schumer, Bob Mueller, Bernie Sanders, etc., Jim Acosta and much of the rest of the national media. And, on the international front, there are other rockheads ... Putin, Xi, Erdogan, Merkel, Kim, etc. So, Trump's metal is being severely and constantly tested at all levels. And those who support him in these contests are a sparse legion. He is being tested as never before.
But he has already won a few shrirmishes ... tax cuts, new NAFTA, regulatory reform, NATO reform, economic growth, monetary policy, global warming policy, economic growth, etc. Yet his detractors are still on the offensive. Their silliness over border security is a perfect example. His opposition on this issue is purely political and unAmerican ... and cannot help his opponents long term (after the shutdown is forgotten).
Most of Trump's critics want him to relent on many of his policies. However, his policies are patriotic and against the myriad special interests in America. He is clearly a populist and a nationalist -- winning strategies as witnessed by how some of his 2020 opponents are beginning to shade their platforms in his direction.
All we can hope is that he keeps his spine for the next two years. If he does, despite being a mule, he will continue winning with the majority of his countrymen.

