Baron De Montesquieu would not support the decision to put a travel ban to the United States. He was never into having one person making irrational decisions such as the travel ban. He thinks that having one person to make the decisions, can eventually lead to them making irrational decision.
It has eternally been observed that any man who has power is led to abuse it.
He argues that if one person is making all of the decisions, this is represented as that person's "power". He believes that if power is shared throughout a group of people, then it would give less power to that one person, and that will lead to less irrational decisions. If power isn't shared, then it could be abused by the one person who holds it.
When power is kept with one person, it's not good, but if it is shared then it is equal throughout the group of people sharing the power.