Back in 1972, when I was a teenager, I campaigned my heart out for Sen. George McGovern, who ran hard to the left of the other Democratic candidates in the presidential primaries. His message of ending the Vietnam War and eradicating income inequality resonated deeply with young people like me. McGovern secured the Democratic nomination only to lose the popular vote by the most lopsided landslide in presidential politics to President Richard (“Tricky Dick”) Nixon…

I know many young people feel as strongly about Sen. Bernie Sanders as I once did about McGovern. All I can say is this: Please do not make the same mistake that my generation did and let a promise for transformational change blind you to the effectiveness of “realpolitik.”

My London-based friend Steven Overman is an entrepreneur who witnessed the Brexit debacle up close. As he told me recently, “Progressive perfectionism is going to destroy us if we don’t keep it in check. It’s great to have ideals, but there’s a far more basic thing at stake: democracy itself.”