This question pertains more to the US, so apologies if I'm speaking from inexperience and misinformation as a bong.

Let's say hypothetically speaking, that 99% of the population of the US wanted a well regulated, monitored accessibility to firearms. This means thorough background checks and an outright ban on mentally incapable individuals. Would the constitution override this democratic desire, or would the voice of the people override the constitution?

If the people are that willing to be disarmed, they do not deserve the right to defend themselves anymore.

“They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety.”

Edit: Just skimmed, thought you were saying they did not want access.

Depending on the extent of regulation, and what constitutes mental illness, it may not really conflict with 2A.

The Constitution can be amended. Since the US is not a direct democracy, all these citizens should contact their representatives and make it happen.

Yeah, I'm pretty sure we already have that. Folks just tend to ignore it out of convenience for their own opinions.