Although George Washington discussed with some men the possibility of his becoming King, the idea was rejected, and the U.S. was founded as an anti-monarchical country. To be in favor of a King is to be against the founding values of the United States. The United States government has always been based on the idea that no leader should be above the law.
The United States was not however founded as an anti-socialist or anti-communist state, since the rise of ideas associated with socialism and communism did not happen until the 19th century.
In fact there were a number of 19th century American groups, most often Christian groups, who practiced socialist ideas. So being an American or a Christian does not mean that one has to be against socialism or communism.
In the 1920s and 30s, during the early development of the Soviet Union, many Americans became anti-communist or anti-socialist, but many Americans were also pro-communist or pro-socialist. In fact a significant rise in socialist ideas in the United States comes in the Progressive Era of U.S. history (roughly 1896-1917). And Franklin Roosevelt, the U.S. President who led the country through the depression and World War II, instituted many socialist ideas into the practice of the U.S. government and helped the country get past the depression.
Roosevelt’s U.S. government made some reprehensible decisions, of course, the internment of Japanese Americans most especially. Being a socialist doesn’t mean making no mistakes.
The rise of anti-communism in the United States begins in earnest with the U.S. government of the 1950s, while the 1960s and 70s saw a resurgence of socialist and communist ideas among the people of the country.
At no time in the history of the U.S. government has a desire for kings and monarchy been a significant part of the government, although the Confederacy did believe to a significant extent in the idea of a white aristocracy.
All of which is to say: if you are in favor of the U.S. President being like a King who is above the laws, your values are historically anti-U.S., anti-American.
If you believe in some degree of socialist or communist ideas, you are simply part of one ongoing tradition in U.S. life, one that has been sometimes loved or hated by different Americans.
The Supreme Court decision earlier this week to make “official” Presidential acts beyond the reach of the law can be said to be a fundamentally anti-U.S. attempt to give the President some powers like those of a King, while at the same time they granted themselves (the Supreme Court) some powers of an aristocracy, something that is also anti-U.S.
Support of the Supreme Court decision is to be against the founding principles of the United States. Donald Trump has come out in favor of that deeply anti-American decision.