Washington D.C. (AP) Joe Biden has taken a big step toward winning enough delegates to be the Democratic presidential nominee. The former vice president swept the seven states that conducted presidential primaries on Tuesday. Those victories have put hundreds more delegates in Biden’s corner ahead of the summer nominating convention. He could lock down the nomination during next week’s primaries in West Virginia and Georgia. Biden’s advance came as voters across the U.S. were forced to navigate curfews, health concerns and National Guard troops. In some cases, they waited in line hours after polls closed.