In failing to demonstrate what they stand for, Democrats fumbled the chance to show why they deserve a return to power, centrists and progressives say.

A generational divide, seen in newer lawmakers’ impatience with bipartisanship and for colleagues who don’t understand new media, has emerged as one of the deepest rifts within the party.

Democrats found themselves in the middle of an all-out civil war on Friday as the Senate prepared to advance a six-month government funding bill to avert a shutdown set for midnight. The Republican-crafted legislation dramatically split Democrats,