WASHINGTON (AP) — Vice President Kamala Harris is moving swiftly to lock up Democratic delegates behind her campaign for the White House after President Joe Biden stepped aside amid concerns from within their own party that he would be unable to defeat Donald Trump. Biden’s exit is a seismic shift to the presidential contest that upends both parties’ carefully honed plans for the race. Prominent Democratic elected officials, party leaders and political organizations have quickly lined up behind Harris since Biden announced he was dropping his reelection campaign. They’re trying to put weeks of intraparty drama over Biden’s candidacy behind them.