>> I thought he had given up on that.

You did?? He's been personally promising to build it 3-5 times a day to tens of thousands of people in every competitive state in the US. It's kind of hard to miss...

>> Why would Mexico have to pay for that? ... It's like building a wall on your property and demanding your neighbors pay for it.

Except the neighbors -- to stretch the analogy a bit more -- have their children, pets and a few spare vehicles in your yard and have become accustomed to browbeating you into not complaining about it. Trump et al. plan on altering this dynamic.