It’s April 16th. Today, we Skimm’d This: More people are getting measles. Lots of the outbreaks are happening in tight-knit communities. Now, public officials are trying to call the shots. But they’re getting pushback. A new 2020 presidential candidate just threw his hat in the ring. You’ve seen that headline before. But this time, it’s a Republican. Trump’s not the first incumbent president to face a primary challenge -- we’ll give you the context. Climate change protesters are bringing London to a standstill. They want the government to stop waiting for Captain Planet. And their tactics are hardcore. A new study explains why our collective attention span is … wait, what were we saying? theSkimm: The measles virus is still spreading, and tight-knit communities are more vulnerable than others. We’ll explain why -- and tell you what’s being done to help. Also: Trump’s not the only GOP candidate in the 2020 race anymore. We’ll tell you why primary contenders can make things messy. Also on today’s episode: climate change protesters in London are getting arrested, and a new study explains why we’re all so distracted. Wait, what?