Nobody wants a stranger breaking into their house, which is we put locks on our doors. And as a result, sometimes we lock ourselves out of our own houses. I even had a friend who once locked himself out of his house twice in the same day. So, we hire locksmiths, give keys to friends, and hide keys in fake rocks to allow us to get around our own security; all of which either increases the cost and hassle of maintaining that security. In other words, the harder we make it for the bad guys to do something evil, the harder we also make it for the good guys to go about their daily business.
There is another element at work in that trade-off, however, which is easy to overlook -- our sense of fairness, justice, and rightness. To explain, let's move the issue from protecting our houses to protecting our streets. We hire police officers, and give those police officers various tools to keep us safe from the bad guys. Again, the more tools that we give to the police (searches, interrogation techniques, check-points, etc.) the more it drives up the cost and hassle -- and the potential for injustice -- for the rest of us to go about our daily lives.
Whether the issue is protecting our homes, or lowering crime rates, or preventing welfare fraud, or requiring voter IDs, the real underlying in each policy debate is how to find the right balance between two competing notions of justice. On the one hand, we don't want to live in a society where the criminals get away; the idea of justice as "catching and punishing the wrong-doers" pushes us towards stricter laws and a more intrusive police presence. On the other hand, we don't want to live in a society where the police can stop and harass us "unreasonably." The idea of justice as "innocent until proven guilty" pushes us towards laxer laws and a less intrusive police presence.
Both notions of justice are valid... most of the time, in fact, moving too far towards one notion while abandoning the other creates problems. This principle is most easily demonstrated in criminal justice: individuals who are treated like criminals start to act like criminals, while individuals who believe that the laws are not enforced at all will use that as justification to commit crimes (the "everybody's doing it" excuse). Instead, we try to find the right balance, with the understanding that by doing so we will occasionally harass the innocent or let the guilty go free.
Those competing notions of justice define a wide swath of our political debates. Through this lens it becomes clear that most Americans are actually not all that far apart on most issues.
We want to both prevent voter fraud and increase voter turnout. We want otherwise law-abiding adults to have modest access to alcohol, cigarettes, and in some cases pot, while at the same time keeping these things out of the hands of kids and addicts. We want the needy to have access to welfare, but don't want people to stop working because of a government check. We want hunters and home-owners to have access to guns, but don't want guns used to commit crimes. In short, most of us understand the need for balance on these issues; our policy debates are only about where the proper balance should be.
Even some of the most contentious issues of our time are still just about finding this balance between personal freedom and preventing bad behavior. Take Obamacare. If people only signed up for health insurance after they were already sick, the health insurance system would fall apart; that's the bad behavior that we are trying to prevent. Health insurance companies solved this problem by denying coverage for pre-existing conditions. In other words, the insurance doesn't pay if you were sick already. But the pre-existing condition rules are unpopular -- it doesn't seem fair to deny coverage of someone's lung cancer because they had asthma as a child. The Obamacare solution is to get rid of denials for preexisting conditions, and instead created a health insurance mandate, which has created a backlash against the injustice of government requiring people to purchase something that they may not want. Once again, the issue here is trying to find a balance between "keeping people from doing bad things" and "personal freedom and convenience." We all agree on what the problems are, and the need for balance; the only disagreement is what that balance will look like.
In short, Americans, whether they are gun-toting conservatives from Texas or hipster liberals from New York, mostly want the same things. We want the freedom to live our lives without government telling us what to do. And we want the government to prevent other people from doing harm. We argue about these things because some people care more about some freedoms than others (e.g. the freedom to carry weapons). But the basic goals are the same, and that means that compromise and civilized debate are possible. In this era of political polarization and gridlock, I find that an extremely comforting thought.