Yes, we are free to say anything. The only restrictions are no threats of violence or plans to commit real crimes. Americans are free to say anything against the government even if it is nonsense and even if it is a lie. Opinions are not restricted.
This is a private website though and the owners will not allow all opinions. The government has no say about that. Sympathizing with America's enemies on Free Republic is not appreciated and can result in a post being deleted or the poster being banned from the website.
I like your tagline!