From cardsagainsthumanitysavesamerica.com:

Donald Trump is a preposterous golem who is afraid of Mexicans. He is so afraid that he wants to build a twenty-billion dollar wall that everyone knows will accomplish nothing. So we’ve purchased a plot of vacant land on the border and retained a law firm specializing in eminent domain to make it as time-consuming and expensive as possible for the wall to get built.

The money comes from their latest holiday “surprise mailers” campaign, which quickly sold out. 

We can only imagine (and hope) that Cards Against Humanity will be doing more stunts like this under the Trump Administration.