I oppose universal background checks because they are the back door to 100% registration (the records will be retained forever and provide a convenient list of gun owners) and registration leads, historically, to confiscation - which is the stated intention of folks like Feinstein. Confiscation would lead to tyranny or the breakdown of civil order, either of which would be the end of our Constitutional republic.
Enough of this supposedly "common sense" incrementalism. I support none of it. Enforce the laws in place, but not a step farther. We know where you intend to take us, a small step at at time, and we're not going there.