By John Wagner and Anne Gearan, Jun. 28, 2015, Washington Post

ROCHESTER, N.H. — At the first glimpse of the rumpled 73-year-old senator from Vermont, the standing-room-only crowd at a historic inn here Sunday morning erupted — leaping up, waving signs and breaking into chants of “Bernie, Bernie, Bernie!”

The scene has become a familiar one as Bernie Sanders makes a most unexpected surge in his bid for the Democratic presidential nomination.

Sanders — a self-described democratic socialist — has seen his crowds swell and is gaining ground in the polls on the formidable Democratic front-runner, Hillary Rodham Clinton. In New Hampshire, where Sanders was on yet another weekend swing, one survey last week showed him within 8 percentage points of Clinton.

Sanders’s emerging strength has exposed continued misgivings among the party’s progressive base about Clinton, whose team is treading carefully in its public statements. Supporters have acknowledged privately the potential for Sanders to damage her — perhaps winning an early state or two — even if he can’t win the nomination.