John Oliver Hilariously Skewers Donald Trump's Plan To Build A Border Wall

The numbers just don't add up.

Throughout this election cycle, Donald Trump has repeatedly promised to build a wall along the United States' border with Mexico to help stop undocumented immigrants from crossing.

While a 2011 Pew survey found that 46 percent of Americans favored building a fence "along the entire border with Mexico," Trump's wall — which he has said will be made out of hardened concrete, rebar and steel — is a different thing entirely. And on Sunday night, John Oliver gave Trump's proposal an honest look. 

Here are Oliver's five strongest (and most amusing) points.

1. The cost would be... a lot.

When Trump first proposed the wall, he said it would cost "$10 billion, which means $4 billion if you know what you're doing." Then he said it'd cost $6 or $7 billion. Then he said $8 billion, then $10 billion, then he said "maybe $12 billion, depending." 

According to a "retired estimator and economist for one of the nation's largest construction firms" interviewed by The Washington Post, the cost would be more like $25 billion. The economist broke it down like this:

Concrete panels: $10 billion

Steel columns to hold the panels: $5-6 billion

Concrete footing for the columns: $1 billion

Roads to deliver the material: $2 billion

Engineering, design and management: $6 billion 

Additionally, the Congressional Budget Office estimates that maintenance for the wall would exceed initial construction cost within seven years. 

2. Mexico will not pay for it.

Trump has repeatedly said that "Mexico will pay for the wall." However, several prominent officials from Mexico have said that won't happen. 

"Mexico under no circumstance is going to pay for the wall that Mr. Trump is proposing," the Mexican treasury secretary, Luis Videgaray, said

"I declare — I'm not going to pay for that fucking wall," Vicente Fox, another former president, told Fusion's Jorge Ramos. "[Trump] should pay for it. He's got the money."

3. A lot of the land along the Texas border is owned by private citizens, not the federal government.

Even the attempted border fence in 2006 ran into tons of problems

Not only does a 1970 treaty prohibit building anything that may obstruct the normal flow of the Rio Grande river, which runs through much of Texas, but private citizens own a large portion of the land on the border. Oliver cites one family who was sued by the federal government and has been fighting to keep the border fence off their land. They weren't alone — hundreds of property owners were also sued.

4. It won't really stop undocumented immigration.

Almost half of undocumented immigrants in the United States right now got here through a port of entry like an airport or border crossing, typically overstaying the visa they used to get in.

In other words, a functional wall would still have limited impact.

5. It won't stop drugs, either.

"As for stopping drugs, walls and fences have not posed much of a challenge to cartels," Oliver said. 

Drug dealers have used tunnels, cannons and catapults, among other methods, to get packages of drugs across border fences. 

Watch Oliver's full takedown here: