What do you call the system in which powers are shared by national and state governments?

Senator Joseph McCarthy is known for starting or contributing to McCarthyism, which is also known as the Second Red Scare. This was when many people were scared of communism and communists  infiltrating  the country. Fear was sparked into Americans and many of them started to question those around them, which Joseph McCarthy did not help with.

Joseph McCarthy preached that communism was a serious threat because communists were a risk to society, as they had no morals, ethics, or religion. He would call out people in the government for being communists, often with no proof or evidence. He even stated that many people in the United States government were communists and that he had a list, but his credibility slowly fell when he started getting criticized for his lack of evidence and his changing stories.

Even after Joseph McCarthy had little to no credibility anymore and nobody really believed him, he had already ruined many people's lives by his false words. He struck fear into Americans and caused many people their careers by accusing them of being communists.