The Berlin Wall was a symbol for authoritarianism, oppression, and contempt for freedom and liberty.
The Trump ‘wall’ is a symbol for fear, bigotry, ignorance, and hate.
See,
Erik, that's what you get when declaring a real thing a "symbol", and debate it at that level. Everyone "sees" into it whatever they like to see. (Never mind, C!)
The Berlin wall was a rather desperate attempt at keeping their socialist experiment viable, and keeping sovereign control over their border and population. It was also inhumane, and an atrocity. Because of that, it also undermined the appeal of any socialist ideas, and thus is also one of the reasons why "socialism" is a smear in much of the world.
The Trump Wall is also a "symbol" of hope amongst the nativist crowd, and Trump's rather desperate attempt at keeping that crowd happy, because otherwise they have nothing of any value to expect from his rule. It is also inhumane, and an atrocity. Because of that, it will (in case it is built, and even due to the plans to build it) result in further decline of the U.S.'s standing in the world, as what was formerly known as the benevolent empire is besmirched and diminished by setting racism and lack of generosity with the downtrodden in stone, or steel, as the case may be.