Bullying is not a good negotiating tactic.
A good negotiation is when both sides perceive that they achieved a fair result. This is only achieved by establishing trust and goodwill long before formal negotiations commence. This is especially true when you know that you will be having a series of negotiations on various matters with the same parties over a period of time.
Trump is not a negotiator. He is a bully. And he is not even an intelligent bully.
He met with Sen. Schumer and Speaker Pelosi in the Oval Office on National television and surprised them with his ultimatum of "the wall or else".
Pelosi and Schumer did precisely the correct thing. In so many words..."Oh yeah? Fuck you. Bye. Come see us if you calm down. See you later".
Trump had no hammer to bully with. A smart person may bully when he knows that he can back it up, but Trump didn't think that through apparently. He's lived his entire life by using threats, puffing out his chest, cheating, not paying up on agreed upon terms, and generally just being a dick. He's built his entire persona on these things.
Well, he's been exposed. Nancy Pelosi had the strength to call his bluff.
And now, no strength will be needed to defeat him. Because when push comes to shove, the entire world now knows that he is full of hot air and pure bullshit. He is nothing but bluster. He showed his hand. The only people who will believe him now are those who are too stupid to know any better, and those types of people will always be around.
This reminds me of when the Wizard of Oz was exposed.