The Democratic Party's most powerful voices warned Saturday that abortion, Social Security and democracy itself are at risk as they labored to overcome fierce political headwinds — and an ill-timed misstep from President Biden — over the final weekend of the high-stakes midterm elections. "Sulking and moping is not an option," former President Barack Obama told several hundred voters on a blustery day in Pittsburgh. "On Tuesday, let's make sure our country doesn't get set back 50 years," Obama said. "The only way to save democracy is if we, together, fight for it." Obama was the first president, but not last, to rally voters Saturday in Pennsylvania, a pivotal state as voters decide control of Congress and key statehouses. Polls across America will close on Tuesday, but more than 36 million people have already voted. By day's end, voters in the Keystone State also were to have heard directly from Mr. Biden as well as former President Donald Trump. And former President Bill Clinton was