Xorkoth
Bluelight Crew
I mean... We don't ban stamp collecting.
...Yet. God damn stampers, hoarding all the stamps so us decent folk can't use 'em

You both make such good arguments. This is why I have flip flopped on this issue so many times. But I will say that anybody who thinks there is a easy solution hasn't thought very hard hard about the problem.
100%, it is a complex issue that has many facets.
A couple of people have mentioned mental health in this thread as an alternative to gun control. Let's say in my hypothetical (for the sake of argument) that the US president has dictatorial power. Can you be more specific about what you'd do re: mental health?
You weren't asking me specifically, but I think the root of the problem is anger, frustration and hatred. People are watching their quality of life slowly slip away, while at the same time being asked to work harder and harder, while the "American Dream" is still being dangled like a carrot on a stick in front of them, but it's receding further and further into the distance. And there are endless narratives about why this is, many of which are designed to shift blame to other groups of people who are also being victimized, rather than at the true source, which is a corrupt kleptocratic elite class who is outright pilfering our quality of life for their own personal gain. Meanwhile these toxic narratives are creating fear and hatred against other groups, be it immigrants, muslims, black people brown people, white people, asians, women, etc.
This isn't the reason for every mass shooting, of course (see the Vegas shooter for example, a wealthy man who achieved success by this established measure. Who knows what went on there?). And mass shootings are only small fraction of gun deaths, they're just the most terrifying and puzzling. The biggest factors are the war on drugs, and domestic violence (the latter wouldn't be solved by gun control regardless, guns are just the most effective tool to kill that are available). The war on drugs has led to violent inner city cultures, which are now well-established, creating cycles of violence and crime. Frustration and helplessness create angry domestic partners who then take out those frustrations on those they love, a pattern which has played out throughout human history.
So, as a dictatorial US President, I would pass legislation to lead to a resurgence of the middle class, a narrowing of the wealth gap and the regaining of the ability for families to be able to provide all of their needs with a single wage earner, leaving one parent with the ability to be a full time parent to better raise their children to be well-adjusted individuals. I would push universal health care or at the very least, affordable health care, and create a focus on mental health. I would decriminalize or legalize all drugs, to take the means of production and distribution of drugs out of the hands of criminal organizations, and relegate drug policy to being treatment-oriented rather than punitive, leading to far less people getting caught up in a prison system that creates disturbed and violent lifelong violent criminals. If we had a society full of satisfied individuals who were generally happy with how things were going, gun violence wouldn't be such a big problem. The problem isn't that there are guns, the problem is that so many people are so frustrated and angry that society has become self-destructive, and violence in a person's upbringing begets violent people.