There is nothing wrong or bad about someone who is a member of a communist party; many perfectly patriotic Americans belong. It's not my thing, but those people have the right to their political and ideological beliefs. It is not inherently traitorous, just different. Likewise, there is nothing inherently threatening or damaging to this country when someone is Muslim.
What we see on the right is a persistent effort to erode our liberty, to attack our fellow Americans, in order to punitively and viciously enforce their notions of conformity --- their very FAILED notions of political and religious conformity, that are utterly and profoundly at odds with the principles of our Founding Fathers, and with our core foundational document, the U.S. Constitution.
We don't need to stamp out Communists; we do need to severely limit the damage that the right wing nuts would do to liberty in the United States. Far too often it is the right, in their efforts to discriminate and to restrict and to penalize, who are UN-American, most notably in their efforts to deny the right to vote to legal voters, our fellow Americans. THAT is the threat the right poses, along with their efforts to erode religious freedom, and equality for people of color, and for women, and for people by intrusion into their gender identity and reproductive choices. The right is the very essence of big government, of unequal and unfair government, and of intrusive government over-reach.