The United States of America was consistently an anti-communist nation, constantly opposing it wherever it would creep up. This was especially the case during the Cold War in which the USA and the Soviet Union were locked in an intense rivalry.
Kilowog was briefly interested in communism when he found politics in America to be too complicated. Especially since a television journalist named Tawny Young tried kicking the Green Lantern Corps around, and he wanted to go public with it on NBC Nightly News, but he was silenced by the other corps members and by NBC as well.
This was due to the fact that it wasn't "proven to be true," even though it was common knowledge. And because of that, she could sue him if she wanted for him going public with it.