There is no reason whatever why he should not be so styled, as, by virtue of his high office, he possesses almost as much power as the most aristocratic ruler of any nation.

Secondly, it would clearly demonstrate the sovereign power of the people; a people who could make and unmake an Emperor, would certainly be highly respected.

Thirdly, the United States sends ambassadors to Germany, Austria, Russia, etc.
According to international law, ambassadors have what is called the representative character, that is, they represent their sovereign by whom they are delegated, and are entitled to the same honors to which their constituent would be entitled were he personally present.

In a Republic where the head of the State is only a citizen and the sovereign is the people, it is only by a stretch of imagination that its ambassador can be said to represent the person of his sovereign.
Now it would be much more in consonance with the dignified character of an American ambassador to be the representative of an Emperor than of a simple President.

The name of Emperor may be distasteful to some, but may not a new meaning be given to it?
A word usually has several definitions.