Fresh from Democratic presidential primary wins over the weekend in three U.S. states, Bernie Sanders said on Sunday he had political momentum that could help him win the backing of Democratic power brokers in his race against Hillary Clinton.

Sanders easily won nominating contests in Alaska, Washington and Hawaii on Saturday. His latest remarks reflect his plan to chip away at Clinton's commanding lead in the number of delegates needed to win the party's nomination for the November election.

Interviewed on Sunday by U.S. broadcasters, Sanders said Democratic "superdelegates," who can change their allegiance, might face pressure to rally behind him because most polls suggest he has a better chance than Clinton of beating a Republican candidate.