There’s this old joke about two comedians who find themselves in a rowboat. One falls overboard. Not able to swim, he starts waving his arms and frantically screaming, “Hey! I’m dyin’ over here!” His friend calls back to him with some advice: “Go dirty!”

We might see this as a metaphor for this year’s presidential primary races. And if you think it’s bad now, just wait until the general election. The divided right is set for a crash course collision with the enraged left in a country that is more politically divided than it has been in decades.

What can we do?

It’s helpful to examine what is happening at a more granular level. Let me propose a quick analysis that looks at three different dimensions of polarization.

First, convincing research shows that polarization is happening on a citizen-by-citizen basis. For better or worse, the average American is becoming more and more internally consistent, more predictable in an ideological sense. A recent Pew study shows that the percentage of Americans who report holding “consistently conservative” or “consistently liberal” views has more than doubled since just the 1990s.

Comedians Jon Stewart and Stephen Colbert hold a rally to mock the polarization of politics, Aug. 28, 2010.

Second, moving up a level of analysis. Both political parties are becoming purer ideological vessels rather than mixed coalitions. Rockefeller Republicans and Blue-Dog Democrats are almost extinct. We know this intuitively, but the data also support it: In 1994, 4 in 10 Republicans were more liberal than the median Democrat. Almost a third of Democrats were more conservative than the median Republican. But today, those numbers have nosedived to just 8 percent and 6 percent respectively.

Finally, it’s not just that the intellectual gulf has widened, between both individuals and the parties. We also really don’t like the people on the opposite side of the gap. Polling shows that a little more than a third of Democrats have a “very unfavorable” view of Republicans; meanwhile more than 40 percent of Republicans hold that view of Democrats.

These phenomena cause problems more dire than just hurt feelings. For example, there is good reason to believe that hyperpolarization has led to a surge in political discrimination that spills over into areas outside politics.

Consider a recent study in the American Journal of Political Science. The researchers asked more than 1,000 adults to compare the resumes of two fictitious high school students and decide which should receive a scholarship. Here’s the twist: Some of the subjects were given resumes that were basically indistinguishable except for one key difference. One of the students headed up the Young Democrats, and the other led the Young Republicans.

What happened? Subjects who identified as Republican or Democrat gave the award to the high schooler who shared his or her own worldview almost 80 percent of the time.

Whether the discrimination was deliberate or unintentional, such dramatic political prejudice suggests real and damaging consequences for fairness and social cohesion. Obviously, we can actively choose our ideology, and so one’s political predilections do offer more substantive information about our character than, say, our appearance. But while dismissing somebody out of hand based on politics may seem less unjustifiable than doing so based on his or her race or religion, it is still not even close to a recipe for social harmony — nor for a policy climate that is conducive to the creativity that our present challenges require.

Who Pays for Polarization in Politics?

The downside to divisive politics goes beyond unpleasantness in our daily lives. The bigotry and contempt bred by excessive polarization make it much harder for America to aspire to the kinds of historic, path-breaking achievements that have defined our proud heritage. As a result, this social pathology imposes a direct and heavy cost on vulnerable people around the world who are not prepared to bear it.

Let me explain. The kinds of achievements in jeopardy aren’t just the ubiquitous DC examples of “pragmatic” policy compromises, such as infrastructure spending or entitlement reform. To be sure, both are important efforts, and they are made more difficult when reasonable disagreements morph into a culture of content. But I think we need to aim even higher.

If you read this newsletter, you’ve probably heard me explain how the spread of American-style free enterprise lifted two billion of our brothers and sisters out of poverty. (If you haven’t, I discussed the details in a recent TED talk.)

This humanitarian miracle is all the more remarkable because it unites seemingly disparate pillars from both sides of the political aisle. We normally associate special concern for the poor and vulnerable with the left, and free markets and global capitalism with the right. But what history teaches us is that only these supposedly “conservative” policies and institutions can fulfill these supposedly “liberal” moral goals. Each polarized camp holds one key to unlock the next antipoverty miracle. But we have to turn them together. We need fierce advocacy for free enterprise and deep moral concern for the vulnerable.

Sounds like a tall task? Well, it is. The stew of American polarization has been simmering for a long time. It’s going to take a minor cultural revolution to fix the damage that has been done. But we must, for our own sake — and the billions of souls whose chances at building financial security and earned success hang in the balance.

Here’s one way we all can beat back the forces of polarization: Challenge yourself to always remember the human faces who are victimized by every uncharitable political attack. As a convert to conservatism who was raised in Seattle, I have many liberal family and friends. Whenever I hear some ostensibly right-wing entertainers try to “fire up” the base by lambasting liberals as stupid and incompetent, I realize they’re attacking people I love. Instead of turning up the volume, I hit “mute.”

Never forget that each of us has agency. We can choose to fashion ourselves and our institutions into islands that rise above the sea of vitriol that has temporarily swamped our politics. The fact that reporters or commentators or some candidates have taken their eyes off the ball of building a better world through an earnest competition of ideas doesn’t mean we should do the same. Much the opposite.

It makes our shared mission all the more urgent.