I hope he wins just so I can see all the crying thats going to happen.

100 billion might sound like a lot but in actuality that's like 1.67% of the total budget. Realistically "saving" that money or spending it elsewhere likely is not going to improve you day to day life any. The US spends 8x that on their military every year. Building the wall and enforcing it would require billions too and it would still require billions in guards and regular upkeep. Beyond that a pissed off Mexican government likely would cut trade and other benefits with the US too. In the end you're probably not up anywhere as much as you'd think. 

It's far better to legalize these people and get them paying more taxes. 

Nope, hell no. There are so many underground tunnels across the border, unless the wall is also 30' deep, not going to do shit.. As a matter of fact there is sewer system in Naco, Arizona that goes across the border that gets used by people smuggling drugs, money, and people all the time. Border Patrol check it a few times a day, but don't have a constant watch on it. Wall is just going to piss off Cartels and cause more violence.

Why bother with a wall when you can just amp up the security?

That said, I would prefer America stop focusing on the middle east and give Mexico as healthy dose of freedom. They're not really controlled by a real government, anyway: the cartel has everything in their pockets. If America were to push the drug lords back to the southern Mexican border and make five new states out of Mexico, then boom: no more illegal Mexican problems, they're citizens. And central America would be a much smaller border to patrol.

This is such a bad idea I'm surpised it isn't Trumps.

You're right. We'll just continue to let the our neighbor to the south rot in drug lord corruption so thick and dangerous that many flee to America in the face of persecution, deportation, and in some cases death. That seems like a much better option, and besides, we've got all that oil to get at over seas. 

So we what? Just start nation building again? Because that just keeps working out doesn't it? There are certainly options that fall between not doing anything, and invading Mexico.

You're right so let's do nothing and amass another trillion in deficits for the next ten years ...

A wall is rudimentary... But I have yet to see a decent alternative.

It will help people who are building it to have a job for a while. When it is finished, people will have jobs maintaining it, and when they figure out it didn't help solve the inherent problems, people will have jobs tearing it down again.

So, the answer is yes, the wall will help people have jobs, but looking at who does a lot of construction and building work in the US, these people may not be US citizens.