Group Protests in National Parks illegal?

After some trouble with blogger, I have finally been able to post another blog.
I have stumbled on another threat to American Freedom...
This Saturday, a number of members of the KKK , also part of the National Socialist Movement of America, met on the battlefield that was home to the bloodiest battle of the Civil War to protest on certain topics. Now I have my own opinions especially against socialism but that is not what threat I am speaking about. As the opinion polls spread throughout the internet, I found one upon the right to assemble at a national park and most who had voted had voted upon making it illegal for protests at National Parks.

Although I do not agree with the opinions of this organization(KKK or National Socialist Movement), I do believe in our First Amendment right to peacefully assemble.
I understand that most American citizens are offended by this group and the message they send, but we can not restrict them from freely speaking without decreasing our own rights. The loss of our own rights, although at first small, would be the stepping stone for the loss of more rights. A controlled society would arise and this controlled society was what the control was meant to detain in the first place. Freedom is a guaranteed right and restricting ones freedom decreases all of our freedom.

As a sidenote, I had read the National Socialist Movement webpage only to find that they do not understand what the meaning of Socialism is. They begin their introduction by depicting the Aryan race and their inspiration came from Adolf Hitler. They do not discuss any poltical/ economic views. How does a group who calls themselves Socialist not have a political or economic view. Namely, they appear to be a hate group. This is only my opinion from reading their website. As I do not want to attract more hits for their website... I do not include a weblink as I usually do.
Are we to reduce our rights for a hate group? Let us maintain freedom.