Sanders and Clinton still head to head

Hillary Clinton holds the Massachusetts Democratic institution.

Bernie Sanders has the progressive grassroots.

It’s an odd balance that’s mirrored in the latest polls, which show a solid tie. The race is rising up to be a test of institutional influence versus grassroots vigor.

Top leaders from Beacon Hill to Capitol Hill stood behind Clinton from the beginning, pitting them against a growing group of Sanders supporters, many of whom were activated four years ago by the message of another senator: Elizabeth Warren.