WASHINGTON (AP) – Joe Biden’s sweeping victories in Florida, Illinois and Arizona are building his delegate lead over rival Bernie Sanders in the Democratic presidential race. And that is increasing the pressure on Sanders to admit defeat and leave the race. The former vice president’s third big night in as many weeks came amid tremendous uncertainty as the Democratic contest collides with efforts to slow the spread of a virus that has shut down large swaths of American life. Biden’s quest for his party’s nomination now seems well within reach. His trio of wins doubled his delegate haul over Sanders, giving the former vice president a nearly insurmountable lead.