Sanders says party leaders may 'rethink' after wins

By Jason Lange WASHINGTON (Reuters) - Fresh from Democratic presidential primary wins over the weekend in three U.S. states, Bernie Sanders on Sunday claimed political momentum he said 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. Interviewed on Sunday by U.S. broadcasters, Sanders said Democratic "super-delegates," who can change their allegiance, might rally be