This is the crux of what drives the chasm. According to many on the left, those on the right should be "reasonable" and for "common sense gun laws."
Let's play that out:
The Right plays ball and bans bump stocks, fixes NCIS, and let's say we go nuts and close the "gun show loophole."
Over the next year, the amount of shootings don't change
Now the professional Left is back at the table, demanding more - so to appear "reasonable" the Right shrugs off the NRA and raises the age to buy a long gun to 21, and bans "hi-cap" mags , only allows for manufacture of 5 round or less mags.
Guess what...nothing - there are still shootings, because there are crazy people and 300MM+ guns out there. So...
Now the Left is back again. The Right responds to the calls for "no more!" "do something" "be reasonable!" "common sense!" and bans the manufacture and import of ALL semi-auto guns in the U.S., limits ammo sale to one box per month, puts in place an optional Federal buy-back program.
Nope...still shootings!
Leading to the outright repeal of the 2A, outlawing of all but shotguns and a turning the optional buyback program into mandatory - you have a 2 year window to give them up or we put you in jail.
Now that the (law abiding, legal) population is effectively disarmed, guess what? Welp, now there is a massive black market for guns, and the shootings, they don't stop either.
Yeah, it's a slippery slope thing. But when people are openly talking about Step 7 being the goal, it's not a hard leap to make. Gun violence is down over the past twenty years even as amount of guns owned have gone up. Mass shootings are up, and that is a Bad Thing, but I put that more on the polarization of our society, the "you're either with me or you're the devil" attitude that people have now than the guns.
As a reminder, A Gun Free America in 5 Easy Steps: