Trump's dumb border wall will never be completely built, even if he gets a second term. Something that big takes too much of a commitment over a long period of time to get it done. Trump's party is not 100% on board with the project, and the Democrats are 100% against. Plus, as long as Trump is in charge, his administration will cut corners and do shoddy work that won't stay up.
The only serious question about "the wall" is how much of the public's money will the Trump Administration light on fire to support this vanity project before the Republicans lose interest.
The only serious question about "the wall" is how much of the public's money will the Trump Administration light on fire to support this vanity project before the Republicans lose interest.