Ready for a long post about activism and democracy? Sure you are!
I absolutely agree with Matt Yglesias that if you feel strongly about an issue, it's a good idea to write to your Member of Congress about it.
More generally, I think people who have never participated in politics generally overestimate how difficult it is to get involved in meaningful ways. Now, to be sure, there are real limits: in a nation of 300 million people, no one can expect to effect change on the first day of activism. But in fact, government policy and the policy positions of politicians change all the time, and change usually happens for a very basic reason: people take action.
So I recommend to people that if they do happen to care about something that it's well worth getting involved. Three recommendations. One is that if it's something that local governments can do something about, that's an excellent place for a solo activist to have quite a bit of leverage, at least in some circumstances. A second one is to join an interest group -- or to start one yourself. The latter is shockingly easy, especially these days, and especially for anyone with skills and resources that are useful (skills such as writing and organizing; resources such as money and, especially, time).
But my main recommendation would be to get involved in party politics. Think that Democrats should return to gun control (the subject of the John Sides post that Yglesias was working from)? Get involved in the Democratic Party, and advocate for it. Think that Republicans should be more concerned about deficits than taxes? Show up, get involved, speak up.
Now, when I say to get involved in party politics, I'm talking about parties, broadly understood -- what in an academic context I call "expanded" parties. That means formal party organizations, but it also means candidate campaign organizations, or party-aligned groups, or even party-oriented media. The same skills and resources that matter on one's own turn out to be extremely helpful in getting involved in party politics, either locally or nationally.
It's true that full-time professionals have a disproportionate share of influence, and some believe that those with one particular resource -- very large amounts of money -- also have outsized influence (my own view is that the latter is generally overstated). And, once again, one must be realistic, which is often quite frustrating: if you walk into campaign headquarters of a six-term Member of the House and demand, after half an hour of working the phones, that she pass the bill you like on the floor of the House next week and get it signed into law...well, that's not going to happen. But put in a few (really, only a few) hours, and before long you'll wind up having a chance to make your case for why she should co-sponsor the bill you want. Get a few of the other volunteers on board (and of course the more hours you put in, the better the chances that you'll do that), and you'll have a pretty decent chance that it'll happen (depending, always, on whether there's strong opposition and lots of other constraints). And every Member who cosponsors a bill makes it easy for the next Member to do so -- the big question on co-sponsorships is often "who else is on the bill?", and so getting one politician on board can often lead to others climbing aboard, as well. Of course, it's not only volunteering in a campaign; you can also become a regular donor, at least if your resources are money, not time. You can write at one of the ideological web sites, and convince others that your issue has been unfairly neglected. You can even get involved in formal party organizations. Local precinct chairs may not have a ton of influence in most places, but the trade-off is that there's usually very little demand for the jobs, so one can get seriously involved pretty quickly.
The point is that political parties in the US tend to be highly permeable for those who decide they want to get involved. And if you look at cases in which the party changed (Republicans and abortion, Democrats and same-sex marriage) you'll find, usually, a mixed bag of top-down elite maneuvering alongside bottom-up activism. Twenty years ago there were essentially no elected Democrats who supported what Democrats now call "marriage equality." Ten years ago, it was a common position; today, it's practically required in many parts of the nation for any candidate who wants to win a Democratic primary. Of course, one of the reasons that changed was that the polling changed. But as Sides tells us, there are lots of issues that poll well; I'd be willing to be that the reason Democrats flipped on this one was that the sorts of people who volunteer for, work for, and donate to Democratic politicians in 1990 rarely believed it was an important issue, while in 2010 they overwhelmingly believed it was a high priority.
Back to parties: one of the reasons that parties in the US are so permeable is because so many individual elected officials matter, and because selecting nominees is relatively, and sometimes extremely, decentralized. That's changed over the years (national parties as such hardly existed, in my view, before World War II), but it still is basically true. Indeed, it's one of the reasons that I believe keeping a strong Congress is so important: because if it matters what Senator Jones and Member of the House Smith say, and if it's fairly easy to get involved in their campaigns in meaningful ways, then the barriers for entry into national politics are very low. And in my view, that's where meaningful democracy can happen. Democracy requires voting, but voting is a very weak act, even in the best of circumstances, and voting on national politicians in a policy of 300 million is certainly not the best of circumstances (I mean, you and I probably can't say, or at least say accurately, what our vote for Barack Obama or John McCain "really" meant, let alone hope that national politicians will figure out what it meant and then translate it correctly into what to do about the debt limit negotiations or Libya or whatever). No, real democracy requires more: it requires ways for citizens to get involved meaningfully if they want to. And in practical terms, that means having political parties open to influence.
So two things: first of all, if you want to change something, good news: in American politics, it really is possible for people to get involved and have a reasonable chance of having an effect. And, second, a principle for reform and political regulation: it's important to keep political parties permeable and open to change.