Eighteen months prior to his death, Kennedy endorsed then Illinois Sen. Barack Obama in the 2008 primary fight -- a massive moment that many credit as a tipping point in Obama's challenge to then New York Sen. Hillary Rodham Clinton. (Obama had convincingly won the South Carolina primary two days before the Kennedy endorsement.)

In that speech, Kennedy cast Obama as the natural heir to the political legacy of his own family.  "I ask you to join in this historic journey -- to have the courage to choose change," Kennedy told a packed audience at American University. "It is time again for a new generation of leadership. It is time now for Barack Obama."

At the time, I wrote that Kennedy's endorsement was the most powerful sort possible. Here's a portion of that piece:

Kennedy, after all, is not simply the senior senator from Massachusetts. He's Ted Kennedy -- last of the brothers of the original first family in American politics (sorry Bill and Hillary) and standardbearer for liberals everywhere. For people of a certain vintage, Ted Kennedy serves as the embodiment of what it means to be a Democrat.
Winning Kennedy's endorsement then, is important for Obama in a number of ways. It -- coupled with the endorsement by John F. Kennedy's daughter Caroline Kennedy over the weekend -- makes a tangible connection in voters' mind between JFK, Robert F. Kennedy and Obama. That is a crucial connection as Obama seeks to continue to transform himself from a candidate into a movement on Feb. 5 and beyond. Kennedy's endorsement also gives Obama some opening to approach a group of rank-and-file Democrats -- union households, middle class whites -- who will be two of the crucial groups up for grabs on Feb. 5.

Kennedy didn't win Obama the Democratic nomination. Barack Obama did that. But, in one of his final major political acts, Kennedy used his outsized influence within the party to make clear who he thought its next best leader was.