Trying to find it but there was a vid explaining that building the wall Trump wanted would cost something like $200 billion and that wouldn't include the cost of policing it. After all, there are vids of people climbing the existing segments and of people cutting holes in it using commonly available tools you can find at any hardware store.
Thus the unqualified campaign promise
"I will build a great, great wall ..." attracted simpleminded voters like a lit candle attracts moths.
What is so horrifying about that is:
- they thought it was a good idea. (I don't recall even Trump asserting it was)
- a large minority of voters approved it by voting for the one that promised it
- Trump never came close to achieving it
- Republican $fund $raising for Trump's wall (the wall Trump promised Mexico would pay for) was corrupt, Trump's wealthy cronies skimming funds raised for wild parties on big yachts
Perhaps one of the more detrimental affects of Trump's lies about the wall is the distraction. There's a serious immigration crisis on the U.S. Southern border. This crisis has endured since before the Trump administration, and it persists years after. Even a wall as Trump described it and constructed a small portion of it is not likely to solve that crisis.
What's needed for that is substantial U.S. immigration policy review and revision.
Example:
U.S. employers are clamoring for employment applicants. Regional job skills training programs open to both citizens and immigrants / non-citizens, with immigration quotas adjusted to keep the training programs fully attended might help solve multiple problems.