I fear you're of the generation denied an honest education in History and Reason (often represented by 'Rithmatic in the 3Rs, because math is the formal language of Reason).
But for other readers, the point is that as long as citizens are armed no politician wedded to any "Ism -- Socialism, Marxism, Fashism, Progressiveism" will have the courage to attempt putting them in chains.  "Ismists" always lack the courage.
That's the point of strength. When you have it, you don't need to use it. No one picks a fight with a stronger opponent. Bullies don't pick on anyone who can fight back.
Of course there's more.  Here's the words the Star cut.
“That danger was well illustrated when Hitler successfully persuaded Germans to allow government to disarm them. Which guaranteed none could later resist his still-armed Nazis. Who forged a brutal Nazi-Fascist-Shinto tyranny that conquered all the world – except America that wouldn’t have been there without that first shot from a citizen-owned rifle”