When a country produces most of their goods for consumption it is called Autarky.
Hitler, Franco and Mussolini were recent fans of autarky and it failed for them. It sounds good but Adam Smith explained that countries should specialise and trade with countries that have also specialised in favourable industries.
A classic example is how China has specialised in producing solar panels with a vast economy of scale. Only a political idiot would want to produce solar panels here where every input cost would be higher or much higher than China but it would be a move towards autarky.
So Donald Trump is sounding like he will be aiming towards a form of Autarky. An important input cost is labour especially cheap migrant labour. So this could interfere with his deportation plans.
