Complex sentence: Early, Markell was far behind in polls and endorsements; the Young Democrats Movement and other organizations allowed Markell to gain early momentum, but these efforts were offset by the endorsement of Carney by the Delaware Democratic Party.
Split into simpler sentences: Early, Markell was far behind in polls and endorsements. The Young Democrats Movement and other organizations allowed Markell to gain early momentum, but these efforts were offset by the endorsement of Carney by the Delaware Democratic Party.