Trump has mooted this idea about financing this ruddy wall. He wants Mexico to pay....they say they won't.
So his next thoughts are that he may impose a 20% import duty on stuff coming from Mexico, like TVs for instance.
But if is to be successful, then its the American people that will be paying that extra 20%, not Mexico itself ! If people refuse to buy any more Mexican goods, then no moneys will be raised to pay for the wall.
He has said the wall will be built paid by American Dollars and then Mexico will reimburse America. If he now introduces the import duty, America will actually pay twice.