As expected, Senate Majority Leader Harry Reid (D-Nev.) on Friday morning officially got behind the presidential candidacy of Sen. Barack Obama (Ill.), calling him a “once in a generation leader.”

Reid’s endorsement means little now that Obama has secured enough delegates to claim the Democratic nomination, but it does mark the party establishment’s acknowledgement that the months-long contest has finally ended. Reid remained on the sidelines for months in the party’s primary rivalry that pitted two of his own colleagues – Obama and Sen. Hillary Rodham Clinton (N.Y.) – against one another.

“Over the past 16 months, tens of millions of Americans from all walks of life have been inspired to support Barack Obama’s historic campaign for president, and with good reason: He is a once in a generation leader who connects with the hopes and dreams of the American people and will deliver the long overdue change that our country desperately needs,” Reid said.

Reid said he couldn’t be more excited about Obama’s candidacy, but also congratulated Clinton for her “tremendous contributions in this campaign and for our country.”

In the same breath, Reid used the opportunity to criticize the GOP’s presumptive presidential nominee, Sen. John McCain (Ariz.), as representing an extension of President Bush’s tenure. Meanwhile, Reid said Obama will bring about change to the nation’s priorities by ending the war and by promoting a more ethical government and a better economic future.

“I look forward to working with him – and an expanded Democratic majority in Congress – to deliver this promise of change to the American people,” Reid said.