As Democratic voters weigh their choices for a nominee to challenge Donald Trump next year, they should take care not to succumb to the “savior” phenomenon. The public tends to develop exaggerated expectations as to what its leaders can accomplish. In a too-common view, if we could only identify the right person for the Oval Office, we could solve our country’s problems.

Candidates recognize voters’ desire for a savior and appeal to it in the way they speak about the presidential role and the results they promise to achieve. Recall, for example, Trump’s declaration that he “alone could fix” the system, or then-candidate Barack Obama’s pledge “to heal the planet.” Projecting strength, conviction, and certainty tends to win the day.

The savior phenomenon leads to misguided, magical kinds of thinking that are more the stuff of fiction than of reality. As a result, it has taken our political system in the wrong direction over time. In particular, we’ve created an “imperial” presidency, with far more power in the executive branch than the constitutional framers intended and far more power than is good for the country.

Unfortunately, the savior phenomenon encourages voters to believe they can solve dysfunction in government simply by changing their elected officials rather than by adopting reforms of the political system that actually could correct the dysfunction. And it can lead voters to choose candidates who promise the most rather than those who will deliver the most.

Of course, the media doesn’t help. It devotes too much attention to the presidential campaign and the personalities of the candidates and too little attention to the kinds of change that really would fix the system.