Many Democrats strongly rebuked Trump’s town-hall tactics, likening it to mob rule. What these critics seem to miss, however, is that Trump introduced an important new dimension to the immigration debate — time spent in the United States — that has the potential to significantly shift public opinion in a more progressive direction.

Trump threw out the number 20 when asking people about what they would do, a seemingly arbitrary number. That’s not random. In fact, our research suggests that 20 years has special resonance among American voters. If someone’s been here that long, even if they arrived illegally, most Americans oppose deportation and favor legalization.