Knowledge of a topic is a prerequisite to useful discussion.

...another RW/NRA/Republican/gunhumping... talking point.

There are a few degrees of removal in the case of firearms. Many folks in the control spectrum between the 'universal registration and BGC' point and the 'muskets only' point don't own a gun, aren't familiar and don't have the right combination of interest and patience to learn. Some of our politicians and media pundits are relying on those realities simply gather followers. For the politician, followers equals supporters, donors and/or voters. For the media followers are readers, listeners or viewers.

An ardent progressive may disparage a religion by pointing out that a certain religious leader has said something unsupported or even completely disproven by science. That same progressive may then go on to make or repeat claims about guns with no scientific data.

When your feelings are echoed by a speaker with charisma and articulated with verve, most folks won't be bother to check the underlying facts. Hell, most will just grab a torch or pitchfork and join the growing mob.