The Mexican people and political leaders have made it clear that they do not support the idea of a wall. The former and current president have both been adamant that there is no way Mexico will fund the wall plan in any way. and the Mexican people support their leaders on the issue.
The whole concept of building a wall to keep out another nation is an insult to that country and plunges us back into the dark ages of history when the Berlin wall was built. Civilized society should be concerned with tearing down walls and building bridges between communities. There is no place for caring people to countenance Trump's antiquated ideals.
Building a wall to seperate us from Mexico was a rediculous idea, further exacerbated by the fact that there is a river and a small mountain range that seperates the two countries (which they also share). Not only that, but Mexico does not want a wall, it is too expenisive to build and a whole host of other problems.
When Donald Trump repeats that Mexico is going to pay for a wall, he doesn't mean he expects the country to write a check. Rather, he indicates that improved trade agreements will increase the flow of income from Mexico to the U.S., providing the money to pay for his border security plans. His choice of words incite debate, but he clearly speaks to why he says Mexico will pay for the wall. There just won't be an agreement between the two countries to do that specific thing.