What does freedom of speech have to do with CPAC?
(hint: nothing.)
In case you don’t know, freedom of speech means the government cannot stop speech that they don’t like just ‘cause they don’t like it.
Freedom of speech has nothing to do with organizations allowing or disallowing groups to have their say.
So if you don't agree with what CPAC has done, withdraw any support you might be giving them. That's your right.