You don't need to go shouting it, but if someone starts talking politics at you, fucking own it. Some coworker is like "trump sucks", say "yeah I know, I'm a communist". Your grandpa says "trump rules", say "no he sucks ass, I'm a communist". You're on a date and they ask who you're voting for? Say "I'm a communist". Cashier asks would you like change? "Yes, I am a communist".
Be open about your politics and lay claim to the title. Be a communist.
What are you referring to?
ineligibility for a bunch of jobs, registration acts, communist control act of 1954, etc.
That law has never been enforced and was ruled as unconstitutional in a lower court, but it has never been repealed and hasn't been ruled upon by the Supreme Court so by technicality in the United States it is still illegal to engage in pro-Communist activism.