You're right, it's just a dumb one.

Why is it dumb?

I feel like even if I tell you why, you wouldn't accept it.  

Fine, then tell me.

How effective do you think the wall will be in preventing people from coming in?  Some people might argue it would be very effective and make comparisons to other countries with walls and their statistics.  However, one thing to keep in mind is that, in conjunction with this wall, there are a number of other things you have to take into consideration.  

How badly do you think they want to get in?  Even with a wall, people will find a way.  The border is also very long, even if you do manage to build the wall, who is going to be patrolling it?  People could just get around/over it if no one is watching.  That costs money too (which the wall will undoubtedly cost much of).  There really isn't any way to effectively make Mexico pay for it unless you think they think they will get something out of it.  That, or you coerce them, making relations between a country you border more tense.  Because that's what the United States needs right now, right?

The wall is also dumb if you take into consideration all the other things he wants to do.  Cut taxes, take many actions that would end up costing money (bombing ISIS, deporting, etc.), keeping the 3 biggest items on the federal budget around, and it goes on and on.

How effect? ASk Israel, who went from 10,000 illegals pouring in to dozens. Hungary went from 20,000 illegals coming then they built a wall and now it's only about a dozen per day.

And Mexico WILL get something out of it - basically, they will not get ruined economically. All Trump has to do is threaten to renegotiate trade deals (which Congress gave the President power to do) and he can have Mexico building a wall before his inauguration.

Sources: http://www.israelnationalnews.com/News/News.aspx/169521

"While 9,570 citizens of various African countries entered Israel illegally in the first half of 2012, only 34 did the same in the first six months of 2013 – a decrease of over 99 percent."

http://www.breitbart.com/london/2015/10/29/hold-hungarian-border-fence-so-effective-illegal-immigrants-are-now-at-pre-migrant-crisis-levels/

"The sudden cut-off for migrants entering Hungary, going from 6,353 to 29 a day in just a week after completing the fence may offer some cheer to conservatives in other European nations who now have a stark example of how effective actually policing national borders can be.

If you look at what I said in the bold, you did EXACTLY that.  

And you saying that Mexico will get something out of it.  No, they aren't gaining anything, they only stand to lose.  Also, you make it sound like only Mexico benefits from the trades, as if the United States would ever do that for a country that actually has a pretty sizeable economy (It's in the top 15 biggest economies in the world).  It seems like you really don't understand the topic you are arguing if you think that Mexico would just go and take it.  The costs of Mexico making the wall would be high, and the USA would only benefit.  USA renegotiating the trade deals with Mexico will harm BOTH USA and Mexico.  Why would Mexico agree?  

I doubt you have an answer, because there isn't any logical one.

If you look at what I said in the bold, you did EXACTLY that.  

And you saying that Mexico will get something out of it.  No, they aren't gaining anything, they only stand to lose.  Also, you make it sound like only Mexico benefits from the trades, as if the United States would ever do that for a country that actually has a pretty sizeable economy (It's in the top 15 biggest economies in the world).  It seems like you really don't understand the topic you are arguing if you think that Mexico would just go and take it.  The costs of Mexico making the wall would be high, and the USA would only benefit.  USA renegotiating the trade deals with Mexico will harm BOTH USA and Mexico.  Why would Mexico agree?  

I doubt you have an answer, because there isn't any logical one.

Your question is mostly non-sense and very easy to split out into points.

You say in conjunction to the wall, there are a number of other things you have to take into consideration.  You then list them as follows :

- Inevitability of Mexicans reaching USA

So you're saying essentially that the USA will be incapable of preventing people from getting into the country?  Is there something unique to all of the other countries who have widely successful statistics regarding prevention of illegal immigration that you're aware of?   All evidence points to the fact that a properly designed wall works incredibly well.  Which is the evidence you've been linked and provided.

You seem to be misunderstanding what I've been saying.  Cherry-picked data is not proof of concept.  Walls are not widely known to be effective as deterrents for immigration.  At the very least, not on its own.  You cannot say what works in one country or two, with totally different environments and situations, will work here.  The most you can do is say, "they can work." 

- Too great a distance to build the wall

The entire US border does not need a wall. This has been discussed ad nauseam and once you identify the segments of the border that do need a wall,  it's not much different distance-wise than walls many other countries have built.  

Another point that I did not specifically state, but even with the claims that you don't need to build a wall all the way across the border, the wall is still large.  

- The wall requires surveiliance 

How does this differ from the current border today?  

How it differs is that if you are committing to a wall to keep people out, you really will have to commit to devoting resources to people not circumventing it either, which is not that hard to do with today's technology.  If you want to claim we're already doing that, then what would be the point of the wall?

- Can't make Mexico pay, no way to strike a deal with them

This has also been discussed ad nauseam.  Mexico absolutely will pay for the wall.  The United States currently has a 58 billion dollar trade deficit with Mexico per year.  That's an easily negotioable stance for the United States.

I don't think you really understand how this works if you think that.  $58b trade deficit doesn't mean we're giving away $58b.  If you can't understand that, then you don't have any right to be arguing it.

-  Wall is stupid when you combine his positions (on cutting taxes, bombing ISIS, deporting, keeping 3 biggest items on federal budget.

None of these are mutually exclusive events.  He can cut taxes, protect the border, bomb isis,  deport illegal immigrants all at the same time.  (And commonly this is what every president does).   As for the (3) biggest items on the federal budget, what are you referencing? 

What you don't realize about Trump's policies is that he makes some pretty big claims.  He wants to cut income taxes across the board, and not by a few percent, but by a very large amount.   From nearly 40% to 25% on the top bracket, and to 0% on most of the lower-middle class.  He also wants to lower taxes on corporations on top of this.  He says to do all this, while he still is saying to keep Social Security and Medicare/Medicaid around.  This, plus his plans on bombing ISIS and these other "tough" actions he wants to take means keeping the Defense budget up, which those 3 make up the 3 most expensive items on the federal budget.  You can look it up and see for yourself.