Seventy-nine percent of Democrats said they would approve of Vice President Kamala Harris becoming the Democratic presidential nominee if President Joe Biden steps aside, according to a new Economist/YouGov poll. Twenty-eight percent of Democrats think Harris would be more likely than Biden to win against former President Donald Trump in the fall, while 32% say Biden and Harris have about the same chances of winning. Less than a quarter say Biden would be more likely than Harris to defeat the former president. The results come as Biden faces renewed calls to drop out of the race from Democrats who worry...