Authors Peter Dreier, who teaches politics at Occidental College and Maurice Isserman who teaches history at Hamilton College warn people who care about the Palestinian people not to protest at the DNC next month if they don’t want to set back their cause: In a democracy, protest movements can play a vital role in reshaping the national debate on important issues. But they have to hone their message and choose when and how to make their case. There were major protests at all three Democratic conventions in the 1960s. Two of them eventually got the results they hoped for. One backfired. In 1960, when John F. Kennedy was nominated in Los Angeles, civil rights protesters, including the Rev. Martin Luther King Jr., carefully orchestrated a 5,000-person march and daily pickets at the convention demanding a strong pro-civil rights plank in the Democratic platform. It was a first at a convention, and Kennedy was cautiously supportive, though it took several more years of protests before he embraced the Civil Rights Act, which became law in 1964, the year after his assassination. When Lyndon B. Johnson was nominated that same year in Atlantic City, civil rights activists, now driving for voting rights, supported the integrated Mississippi Freedom Democratic Party delegates in place of the all-white regular Mississippi delegation. They didn’t unseat the regulars, but their impact on delegates and public opinion was undeniable. A year later, with Johnson’s support, Congress passed the watershed Voting Rights Act. The convention protests of 1960 and 1964 followed a sophisticated…