I am not sure that people who click on the link are pro-gun, but they are people who care about the issue. The general public really doesn't know much about the constitution and cares less.
Example from someone who should know: Chris Mathews badgered Mike Huckabee about his support from Christian fundamentalists, saying the Constitution forbids a religious test for public office. Mathews quoted the constitution correctly but missed the point (deliberately?) that it referred to a religious test in the law. In England a candidate for public office, including military or naval officer rank, had to belong to the Church of England; Roman Catholics were specifically prohibited from holding any office. That was the kind of thing the Constitution banned here; it does not prohibit any voter from making his or her choice based on religion or anything else.
Jim