The constitution, as it has been interpreted through our history, allows states and the federal government to pass laws that reasonably limit rights provided the curtailment is in pursuit of a legitimate government purpose and narrowly tailored to be the least restrictive alternative. Debate the constitutionality of Brady all you like, but I would encourage you to start that debate by reading both the constitution, the Brady Act, and the opinions ruling on it. Having done that, I would say: Yes, you absolutely can be required to get a permit to exercise a right guaranteed under the constitution.
I am a gun ownership proponent, have looked pretty carefully at the law and personally think that there is room for debate regarding the purpose and intent of the 2nd amendment. However, I am happy that the current state of the law gives me the right to own, conceal and carry. I lived in Chicago for a long time and am extremely happy that the Supreme Court struck the laws in DC and Chicago that essentially limited the right to bear arms to criminals. If even ten percent of people carried Holmes might have been pasted to the wall of the theatre after shooting a few people, but no way he shoots 70.
Despite this, I wouldn't mind seeing a requirement for four or five references before purchase. The whackos seem to never have friends and the people they do run into often recongize that they are unstable. What if we made them come up with five references from any adult who would say that they ought to be able to buy a gun -- and dropped those references into a database with some liability limitation for the people giving the reference? How many of the recent mass shooters would be able to get four or five references? Not Holmes, nor Cho. Seems like a reasonable way to achieve a legitimate purpuse that is narrowly tailored enough that I would be willing to put up with it.