The Wall was less of a border policy measure, but a taunt, a boast how good Trump was as a deal maker. “And Mexico is going to pay for it” was just a way of Trump saying “I’m so good I’m going to keep those people out and they are going to pay me to do it.”
Two years later, he shut down the government over 5.7 billion dollars, said he’d never sign anything without border money, and 35 days later he signed something without any money. He put himself in a terrible position: doing an unpopular thing (shut down), for an unpopular policy (the wall), came out and said he was happy to do these things, then fully capitulated. From a deal maker standpoint, it was an embarrassment.
It gets framed as a win for Dems because everything has to be framed that way because we are stupid, but this is the same person negotiating with North Korea, China, etc. And we just saw him negotiate on something out in the open, and he did everything wrong. Pretty red flaggy.