Can Mitt Romney really deport 12 million illegal immigrants? Does John Edwards really expect to seal the U.S. off from globalization and make our economy "fair"? Why, when talking about complicated problems like illegal immigration or rising income inequality, are the solutions we hear from presidential candidates -- all smart, well-connected people with abundant access to real answers -- so absurdly simplistic? Shankar Vedantam writes in today's Washington Post about the science behind this strange (if standard) rule in politics. It turns out that simplistic answers -- though disastrous once a candidate becomes an elected official -- really do win elections.

In a study that examined State of the Union speeches delivered by forty-one different U.S. presidents, researchers found that leaders need to walk a tightrope to stay elected yet get things done in office:

The study found that in the first three years after a new president takes office, his speeches displayed higher levels of complexity compared with addresses in the fourth year in office. In the first three speeches, presidents were more likely to acknowledge other points of view, potential pitfalls and unintended consequences. In the fourth year, however -- as they were about to run for reelection -- the complexity of their speeches plunged.

Not only that, but American presidents who showed a sharper decline in complexity were more likely to be reelected than those who continued to acknowledge that the challenges facing the nation were complex.

This even holds true for revolutionary leaders. Figureheads tend to win power with a simple message but quickly fail if they do not adapt to the complexities of their new role. The rush to over-simplify for the public is not really the fault of leaders themselves, Vedantam argues, but of the people who do the electing. This is a game built into the democratic mechanism.

So the next time you hear presidential candidates say simplistic things that people want to hear, remember that they are merely responding rationally to the incentives that voters give them. The disturbing question is not why politicians pander, but why pandering works -- and for that we need to look in the mirror.

This finding is dispiriting for advocates who champion listening to the public's voice on complex issues. It will, I suspect, always be an uphill battle to get public support and attention focused on more than the headline -- or the lede at best -- of a difficult issue. But it does seem that, while advocates for better immigration policies or climate change may never get the public to think through all the options and their implications, they can succeed at moving the headline itself away from vapid chatter and simple-minded bromide toward the makings of something worthwhile.

In other words, don't expect the public (or your political champion) to plumb the depths of your issue. Rather, focus on giving them something worthwhile, if straightforward, to work with.