I can choose between 350 channels on my television, 170 stations on my satellite radio, 10,000 books at my local bookstore, and millions of websites on the Internet. But on my ballot I have only two real choices. I can vote for a Democrat or I can vote for a Republican.

In an age when even ice es in 31 flavors, having only two choices in electoral politics seems anachronistic. But the limitation has an ironically beneficial effect. For as divisive as politics can be, nothing else has such power to unite our pluralistic nation.

From magazines to coffee to houses of worship, our consumer-oriented culture provides us with an unlimited number of choices. Chances are that you don’t watch the same TV shows, listen to the same music, or attend the same concerts as your neighbors. While the range of choices can be individually beneficial, it can be socially atomizing. In the 1950s if you lived in Green Bay you rooted for the Packers — just like everyone else in Wisconsin. Now with satellite broadcast, your favorite “football” team is just as likely to be Manchester United.

The expansion of choices has affected almost all major areas of life, except for one. In electoral politics you are forced to choose between the two dominant political parties. (Technically, other parties are listed on a ballot but the choice is still effectively limited to the two parties. See addendum.) Whether you are a proto-Marxist a theocratic Domnionist or a socially liberal libertarian, your choice of parties is limited to the Democrats or the Republicans. The choice may be nothing more than a vote for the lesser of two evils—Beelzebub rather than Lucifer—but making it requires you to band together with others of varying degrees of unanimity.

This is an admittedly thin thread for binding a nation. But just as a spider’s web posed of threads that are surprisingly elastic, the web of electoral politics posed of ties that are thin, though remarkably strong. Conservatives, for instance, often scoffed at the deranged hatred of President George W. Bush by the political Left—just as liberals often mock deranged hatred today for President Obama. Yet such raw emotion and focused animosity toward the President has had an incredible ability to unite divergent factions within the divergent coalitions.

This is not to say that such unity is positive or can be used to good effect. In the case of hatred from Bush or Obama, I believe it is neither. It does illustrate, though, the power that electoral politics can have in bringing together an otherwise fragmented culture. Fortunately, this effect is not merely within the political parties themselves.

Most choices tend to be made in private and affect other people, if at all, only indirectly. For example, if I choose to buy coffee at Dunkin Donuts rather than Starbucks it has only a negligible economic impact and a statistically insignificant affect on your life. Even if millions of people make such a choice it will not—unless you own stock in Starbucks—make much difference to you personally.

Political choices are different. My vote may be statistically insignificant but if millions of people make the same choice it will directly affect your life. You have a stake in my choice and therefore have more incentive to voice your opinion. This provides us a reason to engage and interact, even if we have nothing at all mon.

Consider, for instance, the people you encounter in your social media circles. On topics such as religion or music, you are likely to engage with those who share your interest. But on matters of politics you are as equally likely, if not more so, to encounter someone who disagrees with your views (unless you live in an epistemic bubble).

There are two reasons that this thin thread of unity is important. First, a diverse nation needs to mon ground on which it can meet, even if it’s only ground on which to argue. Second, the clash of views often leads to spillover into other interests and topics. Engagement over political views often leads to debates on cultural and religious issues as well. Over time we learn much more about our fellow citizens that just their political beliefs.

Whether we find ourselves in disagreement or in harmony, we invariably find out more about other people than we otherwise would have done. e to debate narrow political topics and leave with our horizons broadened. It may not be much. Often more heat than light will be shed on the issues. But in a nation of choices, where we can narrowcast our way past our neighbors, it’s good to find something that we have mon.

Addendum: Casting a “protest vote” for third-party candidates is essentially casting a vote for the party you like the least. For example, say you prefer the Democrats to the Republicans but choose to vote for the Green Party candidate. Since the Green candidate will not win, you vote effectively reduces the vote for the Democratic candidate (your second favorite choice) by one. Had you cast the vote that way, it would have offset a vote for the Republican.