Each human being comes to Planet Earth sovereign, subject to no other without explicit permission. It’s “natural law”, the rational and logical analysis of what can and what cannot make sense.
Each human being comes “equal”, i.e., human, not horse or pig, not broccoli or tree. Each human being comes unique, unlike any other, as with snowflakes. So each human being comes endowed by the Creator or “nature’s God” with the unalienable rights to life, to liberty, and to the pursuit (which means “earning or achieving”) of happiness.
And each comes with the unalienable right to self-defense of those rights. From whence, then, comes the “right to bear arms”? The 2nd amendment is but iteration, re-statement by the Founders of what was granted by the Creator.
A frail octogenarian woman still has the right to self-defense, and the great equalizer between her and an early-20s gang banger is a firearm.
There are two categories of people who oppose the right to bear arms: (1) those who seek more political power over We the People, and (2) those with unresolved personal mental-health issues. The latter need psychological help with their issues. The former make crystal clear why We the People must not let them win.