I would love to see the abolition of all borders in the future. There is an uncanny link between nationalism and racism. Would not build a wall.
The abolition of all borders wouldn't be a good idea. A wall isn't good either. I think borders are important especially in the middle east where they are fighting over borders because they want to remain separate. Here, in the US, state borders don't mean all that much, in fact, they are just signs on the side of the highway with nice little pictures on them that say
"Welcome to _______" but, borders of countries are important.
Take the border between the US and Mexico that everyone likes talking about nowadays as an example. The border, if controlled properly, should be able to stop most illegal immigration. It can also protect agriculture along the southern coast with its fruit and vegetable check and should control the flow of immigration.
Also, Without borders, people wouldn't know where one form of government starts and stops. I mean, what about places where countries that are democratic have communist or anarchist neighbors? Where would the democracy stop and the anarchy start?
There are a lot of problems that might be solved with the dissolving of all borders but many would arise as well. Until these problems solutions are found, borders should probably stay put.
***edited to fix quote tag and page -tiger