Sen. Bob Casey (D., Pa.) told CNN's Wolf Blitzer that the Democratic party has the "propensity" to get nasty as the race for the Democratic presidential nomination continues.
"Well, Democrats have that propensity. I've been in four contested primaries in my state—I know what it's like," Casey said. "We also are good at unifying, and I think people will be together starting in Pennsylvania after Tuesday."
Casey said that Hillary Clinton will win in Pennsylvania and that the party should start getting ready for the general election.
When asked if Sen. Bernie Sanders (I., Vt.) should drop out of the race and unify behind Clinton, Casey said that it was up to Sanders, but the sooner the party could come together the better.
Clinton swept her adopted state of New York Tuesday evening and received 58 percent of the vote while Sanders received 42 percent of the vote. Clinton also leads Sanders in an NBC News-Wall Street Journal poll by two percentage points, down from her nine-point lead last month.
Pennsylvania, Maryland, Connecticut, Rhode Island, and Delaware primaries will take place April 26. If Clinton wins those states, it would be difficult for Sanders to find a path to the nomination.