Why do so many white, working-class voters vote against their interests at times? In other words, why do they vote Republican?
1. Democratic stupidity on wedge issues that are proven losers, such as gun control. Sorry, folks, but many people don't trust that future governments can be trust with a monopoly on force. On that issue, they're right, even if on balance, the Democrats are still the better party. Governments are made up of people, people fuck up, and if you don't trust individuals with weapons, why the hell would you trust institutions with a track record of violence, abuse, war crimes, genocide, etc.?
That said, I fear the GOP far more as potential tyrants than any Democrats, and I find it ironic that the ones who most want to disarm citizens are the ones who are least likely to abuse that monopoly. Still, it's a prudent man or woman who looks ahead and human nature is immutable short of macro evolution, so it's wise to avoid crazy ideas like gun bans.
2. Blue-collar workers worried about the environmental movement's effects on their jobs. To you and me, it's a no-brainer that climate change and pollution are real threats to our future. To someone whose job seems endangered by the EPA, however, it's easy to buy something that might keep them employed.
3. Failure to paint the Republicans effectively in economic terms as the party that wants to kill jobs, lower wages, and cause their sick relatives to not get proper health care. That's the line of attack that should be followed. Also, failure to hit them harder on failing to provide benefits to veterans who have been in these wars that they've fought for us under Republican administrations.
4. These government shutdowns. The human and financial costs of them need to be presented in real terms, ideas that the voters can see how it affects their daily lives. Furloughed defense workers, soldiers endangered, national security harmed. That sort of thing. The very fact that so many Republican veterans haven't turned against Ted Cruz despite his role there is symptomatic of this problem.
5. Too much focus on the GOP tax cuts' impact on the debt, instead of connecting the Republicans' lack of fiscal conservatism to the rich cheating on their taxes already, painting them as the welfare queens that they really are, and showing how flat and sales taxes are bad for the middle class and working poor. Too many believe that these would cut their taxes and simplify what they see as a rotten and unfair system. It IS rotten and unfair, but not for the reasons that they believe. These voters need to be shown in regular ad spots that tax cuts for the rich are at THEIR expense.
6. Inattention to men's issues. The war on women is real, but so is the war on working-class men. Both are harmed by the radical social and economic agenda of the far right, and those bemoaning what is done to American men often have an easy scapegoat in feminists, given to them courtesy of the religious, evangelical right. This needs to be driven home, constantly. For instance, equal pay for equal work HELPS men, because wives have more to bring home to the household, easing the burden on the whole family and ex-wives need less alimony if they're paid more. This is not just a women's issue. It's a men's issue, too.