Romney was expected to sweep all five states, where a total of 231 delegates are at stake. Turnout was low in all five states, according to local media reports.
Earlier today Newt Gingrich suggested he might reassess his campaign depending on the results in Delaware, where both Gingrich and wife Callista have spent a great deal of time campaigning. Tonight, after placing a very distant second — taking 27 percent of the vote to Romney's 56.6 percent, Gingrich echoed that message.
"Callista and I got into this for our grandchildren," he said. "I want you to know over the next few days we're going to look realistically at where we are at. We're going to be in North Carolina all week. I also want to do that as somebody who is a unifier and somebody who is realistic."
The votes are still being tallied and the delegate projections have yet to be finalized, but with Romney carrying more than 50 percent in each of the five states, it is clear that Romney will undoubtedly pad his already insurmountable delegate lead this evening. He had 698 delegates coming in to tonight's primaries, ABC News projects.
Romney's attention has turned to the general election. In his speech tonight in New Hampshire, which will be a swing state in the fall but was not voting today, Romney focused his attacks on President Obama, as he has done in the past several weeks, since Rick Santorum dropped out of the race.