The debate in politics about whether endorsements matter is kind of like the debate in football about whether coaching matters. Most of the time, it matters on the margins. But sometimes, people, place and purpose come together, and an endorsement really stings a rival.

I think Sen. Ted Kennedy's endorsement of Barack Obama, today, coming two days after South Carolina, coming at a time when, thanks to the ingenious placement of a New York Times editorial the night after a hard-fought and well-won victory after weeks of racial acrimony, well, this sentence has to end somewhere. Ted Kennedy matters. Forget the casual association of his name with blocks of Democrats Obama needs to do better with, like union members and downscale workers, Latinos and older liberals.

It allows Obama to further clarify what, for him, the Old Politics is all about -- that is, it allows him to separate the Politics of the Clintons from the politics of Democrats before the Clinton administration -- a party dominated by the Kennedy dynasty and their patrons, in many respects. And the The New Kennedy is even more of an attractive figure, in some respects. He has never shirked the responsibility of Democrats to beat up Republicans, but throughout his career, he has demonstrated a long arm for compromise. Most recently, He worked with President Bush on No Child Left Behind and with Mitt Romney (whether Romney currently accepts it or not) on health care in Massachusetts.

In some ways, there may be no member of the Democratic pantheon who better reflects the consensus-based, transformative and activist-oriented politics that Obama embraces.

And so Kennedy can be an enormously effective advocate for Obama because he understands, and, indeed, has practiced the New Politics.

There are 8 days till Super Tuesday. Thanks to Ted Kennedy and Camelot, Obama's won two of them. And because momentum seems to attenuate quickly, rolling out these endorsements when the spotlight was already on Obama extends the battery life for another 24 hours.

On a more visceral level, Ted Kennedy's endorsing your opponent is probably as big of a rebuke as there is in the Democratic Party -- even bigger than South Carolina.

Now -- it is true that Camelot, as many Democrats remember it, is idealized, and that Kennedy himself has done bad things to himself, his family and others, as Fox News and Republicans will no doubt remind. But voters know this -- they did not, after all, nominate Ted Kennedy in 1980. And so it probably does not bear any more mentioning in a political column.