Millions of people took to the streets in America for the No Kings protests on Saturday. It’s said to be the largest peacetime demonstration in US history. People are protesting against President Donald Trump’s policies, and say events like these help mobilize the opposition against his administration. So, the protests were huge but did they have what it takes to affect change? Lisa Mueller, the author of The New Science of Social Change: A Modern Handbook for Activists, talks about what makes the most impactful protests.