COLUMBUS — Support in the Democratic presidential contest has unified behind former Vice President Joe Biden, and Republican President Donald Trump has no serious rivals.
But there's still plenty to watch Tuesday as Ohio wraps up its long-delayed primary election and Maryland voters pick a successor to the late U.S. Rep. Elijah Cummings.
Mail-in voting systems that could be used in November will be scrutinized. If in-person turnout surges due to postal glitches, states may have to regroup.
Also, delegates gained by Vermont Sen. Bernie Sanders could heighten the former presidential contender's influence on Democrats' policy agenda.
