You're a sensible person, but you're falling into the trap most sensible people who vote Democrat fall into concerning gun control. It's probably not that important to you personally, so you don't follow it closely, and so you miss what's really happening, what the long term trend is.
There has always been a faction in US politics that favors more gun control. It got serious and gained significant traction in the post Civil War south, and there's been an incremental chipping away at the 2nd Amendment ever since. I've written about this on SDN many times before, so I won't rehash it all. The short version:
We've endured a nearly continuous trajectory of more and more restriction, ultimately aimed at a complete ban of privately owned firearms, born mostly from racism and classism. Start with the laws aimed at disarming and keeping newly-freed black slaves down in the south in the 1860s. Some other notable milestones of "reasonable commonsense" gun control would include the 1934 National Firearms Act (which heavily taxed many guns so only rich people could own them), the 1968 Gun Control Act, the 1986 Hughes Amendment to FOPA, the 1994 "federal" assault weapon ban, and everything the state of California does between Monday and Friday (inclusive) every single week the state legislature is in session.
You're a sensible person, and you probably genuinely believe that none of these steps were aimed at banning private ownership of firearms. These people aren't stupid. They know an outright ban can't happen overnight. So they chip away bit by bit, pushing as much as they can get away with. Sometimes they overestimate how much they can get, and they fail (e.g. post Sandy Hook efforts) but they just try again. Sometimes they bite off the right amount, and we get magazine capacity bans, the federal AWB, etc.
But please recognize - the ultimate goal
really is registration, a ban of new manufacture/purchase, and finally confiscation.
I have been generally sickened by the antics of the Republican party over the last decade or two. That's not to say I love the Democrats, with their own pandering faux-championing of the poor and their own silly misguided (but mostly well-intentioned) policies.
But their incremental, insidious efforts to push more and more gun control - especially the cynically opportunistic attempts like we witnessed after Sandy Hook - are absolute dealbreakers for many of us. Hardly a day goes by when somewhere in this country a Democrat tries to turn ME into a felon with a new law. Not drug dealers, murderers, burglars, rapists ... me.
TWO WEEKS AGO California's Senate
passed a law prohibiting the manufacture and sale of semi-automatic rifles.
A competition rifle I've owned for years is illegal under this new law. It's the last thing anyone would ever use to commit a crime. It cost about $1500. It has about 8 pounds of lead weights added to it for balance and inertia. It's used in a class of competition that has been sanctioned by the Civilian Marksmanship Program for over a century. And California is making it illegal.
The truth is that the Democratic Party
really is making concerted efforts to ban guns.
Every once in a while one of them lets slip the real goal.
Australia has chosen the register, ban, and confiscate path of gun control, and both Hillary Clinton and Barack Obama have praised it:
When Democrats comes right out and claim no desire or intent to pursue gun control, we don't believe them, since they've been lying about it for decades. We need look no further than the current president, who repeatedly denied any plans to support new gun control legislation, only to make a major push for it about a month after he was safely re-elected. We need look no further than the current (presumed) presidential candidate, Hillary Clinton. We need look no further than the two California Senators, Feinstein and Boxer, who've been "serving" in the Senate since the early 90s.
You want to stop Trump? You want the positive pieces of the Democratic platform to proceed? Start with an honest assessment of what's really happening in your party concerning gun control. The Democrat party desires and works toward incremental, progressive gun control with the ultimate goal of a complete ban.
This subject alone is responsible for a huge number of Republican votes, including mine.
Your party
really is working to ban private firearm ownership in the United States. Don't agree with that? Don't like it? Don't want to keep losing votes because of it? Good. The first step to changing it, is to acknowledge that it's happening.