Donald Trump speaks out against "political correctness" on the left in his trademark nuclear fashion, yet it is Bernie Sanders, the presidential candidate of the left, who leads by example.

Sanders spoke Monday to 12,000 students at Liberty University, invited by the prominent conservative Christian college founded by televangelist Jerry Falwell to address its weekly convocation. It was a gracious outreach and response. Sanders spoke of their common ground. "How can we talk about morality, about justice, when we turn our backs on the children of our country?" he asked. And Sanders didn't shy away from his support for same-sex marriage and abortion rights. He got an enthusiastic response from the audience when it agreed with him. When it didn't, the Vermont senator was listened to respectfully.

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Later at a community college in Iowa, President Barack Obama spoke directly to the intolerance of opposing views so in vogue among the academic left. Obama said it was wrong and closed-minded to reject or shout down speakers who are conservative, who write books with language that offends African-Americans or who somehow send demeaning signals to women. "I don't agree that you, when you become students at colleges, have to be coddled and protected from different points of view," the president said. Instead, argue for your position. "But you shouldn't silence them by saying, "You can't come because I'm too sensitive to hear what you have to say.' "

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Intolerance has taken root across the political spectrum at the start of the 2016 campaign. That's why an ad released this week by Jeb Bush seems refreshing. His Mexican-born wife, Columba, speaks in English, her second language, while Bush speaks in fluent Spanish. Yes, it's a smart political strategy to highlight himself as the GOP candidate who can appeal to Hispanics. Nonetheless, it sends an important message about tone, one that says divisiveness isn't the only road to success.

Wednesday night is the second Republican presidential debate. While zingers have proved successful at attracting a following, a civil discourse might be a winning strategy, too. Can we all turn off our outrage machines for a little while?