Not unless Congress approves a tax on those remittances - Trump could not do so himself.
Now, there may be other ways a president could recoup the cost of building the wall without the assistance of Congress - withholding foreign aid payments, etc. - but no president could constitutionally impose a tax on remittances on his own.
You think people are not aware of those facts? If yes, what’s the point in stepping on the sentiment? If no, then you should be aware that longtime FR members are well-aware of the process.
Of course, it goes without question that Donald Trump will propose legislation on Day One of his term and request a bill be sent to him for his signature that imposes a tax on outgoing remittances.
I am confidant Donald Trump will also on Day One propose a host of other tariffs and taxes that will be imposed on American companies unless they repatriate their overseas operations and capital.