"The turmoil on the left mirrors that of Republicans in the first two years of Mr. Obama’s administration, when Democrats controlled all the levers of government and left the Tea Party-inflected Republican Party to thrash around in impotent protest, raging with an energy that eventually propelled it back to power," the N.Y. Times' Jonathan Martin and Alex Burns write.

The big picture: "But some Democrats see the moment in even more sweeping terms, akin to the era following the Vietnam War and Watergate, when the reaction to a controversial Republican president triggered a moderate and liberal backlash. That movement delivered dozens of new seats, but it also unleashed a generational changing of the guard that jolted party leaders."

Be smart: "What worries some Democratic elders ... is that activists will harbor unrealistic expectations of what sort of policies newly elected progressive lawmakers can push through in a still-divided capital."

• John Lawrence, former chief of staff to Nancy Pelosi and author of a book on the Watergate Babies, "The Class of '74": The activists "say to new members, ‘You won because of us.' Actually no, typically you win because you were able to win moderate voters disgusted with incumbents.”
• "There is also a group of younger Democrats uneasy about the party drifting too far left.

P.S. ... N.Y. Times: "A page featuring results from New York's primary elections was the week's most popular article. More than half of readers checked results from their phones, and over 40 percent found the article via search engine."