Nine states and the District of Columbia are voting. Tuesday’s elections will be the largest slate of presidential primaries in almost three months. Voters and campaigns alike will be asked to navigate coronavirus concerns and curfews in place amid protests of George Floyd’s killing. There’s been a sharp increase in mail balloting as voting takes place from Maryland to Montana. Many political groups are focusing on Pennsylvania, which represents a high-profile test case for the November general election. Former Vice President Joe Biden needs to win 89% of all delegates at stake on Tuesday to formally clinch the 2020 Democratic presidential nomination.