U.S. Senator Bernie Sanders was the target of his rivals for the Democratic presidential nomination in the latest televised debate held Tuesday in Charleston, South Carolina. Sanders has emerged as the national front-runner after victories in the first three nominating contests, but his rivals contend that the self-declared democratic socialist would lose to Republican President Donald Trump in November's national election. VOA's Richard Green has the latest chapter in 2020 presidential election. VOA Khmer's Moryvan Ly narrates in Khmer.