I don't even own a gun, but I'm not a fan of repealing the 2nd amendment - governments trend towards tyranny; history has shown us this time and again. And while I agree that a guy with a rifle is not going to be able to keep an organized army from taking whatever land they wish, he can make KEEPING that land a living hell. No, the answer to this is much simpler. "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed." So, as the amendment states, well regulate it. Guns are a constitutional right, but there can be exams and training required to get one, licensing fees and background checks to purchase one, and ongoing assessments to keeping one. I think a really easy solution to this (well, with the GOP nothing is easy) is just to say that anyone who has a gun has to be part of a militia. The militia is licensed and insured. One of your militia members goes nuts and shoots up a mall, the militia is on the hook for it.
A guy with a rifle? Tell that to the Afghans. They drove the British out in the 19th C.; the Russians in the 20th; and the US and NATO in the 21st. Of course, governments love disarmed populations. My family had to fight a shooting war against the KKK in the 1910s-1920s. We aren't Black. My grandfather angered the KKK by marrying the daughter of a converted Jew. The KKK considered this to be "race mixing" and tried to lynch him, and run most of his relatives out of the county. The only thing that prevented this was being able to shoot back, which also saved some local Catholics. (This is the same KKK that in Oregon tried to outlaw cross breeding chickens as "miscegenation.") Under Woodrow Wilson, the KKK was much praised and admired by the genocidal eugenics fanatics of the "Progressive Movement." The police, the sheriffs, the elected officials in many places were members and supporters of the KKK. Look up Tulsa, OK, for a particularly flagrant, urban example of the movement. In other words, the KKK was the ANTIFA of the 1910s-1920s - permitted to burn, loot, murder and destroy while the police ignored or even protected them. In the US, the paramilitaries tend to belong to the Progressives, not the conservatives. Conservatives believe in law; progressives believe in ignoring the existing laws and writing those more to their convenience.
To program is to be.