If you follow the premise that states can regulate firearms because it is only a "federal" constitutional right then on the same token state could ban religon, free speech, reinstitute slavery etc.
If you follow the premise that states can regulate firearms because it is only a "federal" constitutional right then on the same token state could ban religon, free speech, reinstitute slavery etc. Not exactly...the 2nd Amendment refers to the rights of the people, and say that it shall not be infringed. The 1st Amendment says "Congress shall make no law".
As for the earlier traffic court argument, as far as I am aware, jury trial still applies in criminal court cases, but not civil court cases - and the 6th Amendment specifies criminal trials.