Sanders picked up his third victory of the weekend after wins in Kansas and Nebraska on Saturday. Sanders' easy victory was announced during the CNN Democratic debate in Flint, Michigan though was clearly trending his way before the debate started. The senator won 64 percent of the vote. Clinton was a distant second with 35 percent.
The senator is well known in New England, where he has been one of Vermont's senators for nine years, so recent victories in neighboring New Hampshire and his home state helped him Sunday.
Clinton still continues to win more racially diverse states, however, and beat Sanders in Louisiana on Saturday.
Caucus turnout was far higher than expected with lines stretching a quarter mile in Portland, Maine. The turnout forced the state Democratic party to allow for absentee ballots so people wouldn't have to stay for a caucus count.
The debate in Flint takes place ahead of Tuesday's primary in Michigan where Clinton and Sanders need to prove their strength in Rust Belt states. Clinton, in Detroit on Friday, promised incentives for employers to keep jobs in the United States. Sanders, despite his winning weekend, needs to win Michigan to prove he's still a viable alternative to Clinton.