With 252 of 433 districts reporting, Obama had 61.4 percent of the vote to 37.1 percent for Republican challenger Mitt Romney, the state government reported in its unofficial election results.
U.S. Sen. Tom Carper easily won a third term. He had 68.9 percent of the vote to 26.7 percent for his challenger, Richard Wade.
John C. Carney Jr. defeated Republican Thomas Kovach with more than 66 percent of the vote, winning a second term as Delaware's only congressional representative.
Gov. Jack Markell won a second term by an even more lopsided margin. He had 72.3 percent to 25.7 percent for Republican challenger Jack Cragg.
The Democratic candidates for lieutenant governor, Matthew Denn, and insurance commissioner, Karen Weldon Stewart, also had more than 60 percent of the vote.