The unspoken rift between Democratic politics’ two most most influential families continued this afternoon.

Never hugely popular with Bill and Hillary Clinton, the Kennedy clan has united in support of one Democratic hopeful - Barack Obama.

Sen. Edward Kennedy backed the underdog for president Monday, saying: “It is time again for a new generation of leadership.”

“It is time now for Barack Obama,” the Massachusetts senator and brother of the late President John F. Kennedy added.

Ted Kennedy stood with Barack Obama, his son Rep. Patrick Kennedy (D-RI) and his niece, Caroline Kennedy (daughter of F. John Kennedy) before a screaming capacity crowd at American University in Washington.

“Like you, we want a president who appeals to the hopes of those who still believe in the American dream,” Kennedy said. “I’ve found that candidate.”

Over the weekend, Caroline Kennedy likened the Illinois senator to her late father in a New York Times editorial.

“I have never had a president who inspired me the way people tell me that my father inspired them,” she wrote.

“But for the first time, I believe I have found a man who could be that president — and not just for me, but for a new generation of Americans.”

Endorsements typically mean little, but does this one actually carry some weight? Follow the jump for reasons it might …

1. The press will be obsessed with the story, with no downside for Obama; media coverage when Kennedy travels for Obama will be significant.
2. Ted Kennedy has a huge following with Hispanics, a big deal in California and other Super Tuesday states, and one of Obama’s weaknesses.
3. The symbolic Kennedy family aura — the ultimate message of change, viability, Democratic legitimacy, and youthful excitement.
4. It sends a message to other senators and superdelegates that it is okay to for Obama — they don’t have to be afraid of the Clintons.
5. Ted Kennedy  has a huge following among working-class, traditional Democrats - not among of Barack Obama’s strengths.
6. The Kennedys are also popular among union households, another of Obama’s perceived weaknesses.