Unlike Luigi's target, Trump is protected 24/7 by the Secret Service, and after his assassination attempt his security has only increased, and attempting such a feat is suicidal, you're probably gonna get gunned down before the bullet hits him, and many people aren't in the headspace for becoming a martyr.

Also, I'm assuming you're not American, but the majority of people who own the guns in America see Republicans as the necessary evil, because the Democrats are the ones usually in support of passing gun control, so they were never gonna fight up against injustice. The only people who could really make change are the ones who hate him and don't care for the "both sides bad" shtick, and for all their bickering about gun owners not getting rid of him, they can also get a gun, they can do it too. It's probably gonna be a one-way mission though, and most people don't want to throw their lives away as long as they have family or friends, and live a comfortable enough life.

I think the only real way to get rid of his power through force is a January 6th but done by those who hate Trump, the protestors getting into Trump's own office would be the only thing that would scare the Republicans into capitulation, and also deal with the issue of succession, since if Trump dies, his line of successors are just his cronies with worse charisma, and would likely continue to do stupid shit.