From NBC's Lee Cowan
NBC NEWS has confirmed that John Edwards will endorse Sen. Barack Obama. Obama's event in Grand Rapids, Mich., is scheduled to begin at 6:15pET, notes NBC's Mark Hudspeth. Obama is expected to introduce Edwards at the event. [UPDATE: "Realistically," Obama is likely taking the stage at 6:35 p.m.]

NBC's Domenico Montanaro adds...
Edwards has 18 pledged delegates, according to the NBC NEWS count.

Even if all of those people voted for Obama, and there's no guarantee they would, it wouldn't quite give Obama a majority in pledged delegates, but it would get him close. Edwards' people are really loyal and might not vote for Obama or Hillary or whoever -- even if Edwards tells them to.

Here's the math...

- The total number for DNC is 4,051 (as number needed is 2,026).
- There are 797 superdelegates.
- So 3,254 total possible pledged delegates
- Therefore, 1,627 is the number needed for majority.
- Obama has 1,599 pledged delegates.
- So that would mean he needs 28 pledged delegates for a majority.
- Edwards' 18 -- even if they all voted for Obama -- would leave the Illinois senator 10 short.
- That's a number Obama would certainly pick up May 20th. Between the contests in Kentucky and Oregon there are a total of 103 delegates are at stake.

(NOTE: Edwards got 7% last night in West Virginia.)

*** UPDATE *** NBC's Andrea Mitchell reports that NBC NEWS has learned that Edwards called Clinton to give her advance notice of his impending endorsement.

One source close to Clinton pointed out "unlike Bill Richardson," reflecting the better relations she has always enjoyed with Edwards. [UPDATE: The source was actually referencing that Richardson didn't call BILL Clinton. Hillary and Richardson had a "tense" conversation. The Clinton camp will not forgive Richardson for not calling Bill Clinton to give him a heads up of his Obama endorsement -- after promising he wouldnt endorse.]

From NBC's Lee Cowan
In the wee hours of the morning -- around 4 a.m. for those wondering how to define "wee" -- a caffeine-deprived television crew transformed a hotel conference room into studio that was seen by millions.

It is a morning ritual practiced a lot recently in the days before a primary or caucus.

This morning was Barack Obama's turn for the "round robin" -- a head-spinning back-to-back series of appearances on Good Morning America, the Today Show, The Early Show and CNBC.

It was remarkable only for this: the senator's demeanor when he walked in. After a long day and a short night, he appeared crisp as ever -- newspapers in hand. He only skimmed the stories about himself -- instead he seemed to focus more on the business pages -- and the international sections.

Aides buzzed around him, a microphone was clipped to his lapel and earpiece to his shirt collar. A make-up person dusted powder across his eyes and nose -- and yet his focus was never broken. He read the paper as if he had all the time in the world -- not that the world was about to spend its' time watching him.

His quiet confidence seemed to suggest he knew what was coming, and he knew how he was going to answer. Questions about Bill Clinton's criticisms were the order of the day. Some asked about his dealings with a Chicago "slum lord" -- Hillary Clinton's words from the debate. There was nothing new in his answers. It's familiar ground for the senator of late.

Despite the cool exterior, Obama is a candidate who seems to tolerate the media -- politely usually -- but little more. He reacts to the press as if he has to, not as though he wants to -- and more often than not, seems to see the cameras and notepads as barriers to voters, not conduits. Perhaps we're not asking the right questions. Certainly there are those he wishes we wouldn't ask. But the exchange seems something he would rather avoid -- not out of fear -- but it seems, out of boredom.
 
When it was all over. He left as politely as he came in, as if it were a doctor's visit. He thanked us all, he shook hands, smiled and went to board a bus to an event that he truly relishes -- campaigning in front of crowds -- not a lone TV camera in a hotel conference room in the wee hours of the morning.

From NBC's Lee Cowan and NBC/NJ's Aswini Anburajan
Rochester, N.H. -- Obama was heckled from the balcony of a theater here. A group of about 10 protestors began to chant "Abortion is abomination." The audience in turn began to shout, "Obama! Obama!" And in the top balcony many started screaming at the protestors telling them to shut up.

Obama from the stage said, "Guys! Guys!" Initially he told the protestors, "I'll talk to you afterwards."

The scene escalated with angry shouts from the audience directed toward the protestors telling them to, "Shut up, go  home." And one man even screamed, "Kill the babies!" An older gentleman put his head down and stuck his hands in his ears. It  was unpleasant on both sides.

The police came after about five minutes and were greeted with cheers by the audience. The protestors voluntarily left chanting the entire time. When the hecklers had left, Obama joked, "Excitement is over, or maybe it's just beginning."

And he said, "Let me just say this though. Some people got organized to do that. That's part of the American  tradition we are proud of. And thats hard too, standing in the midst of people who disagree with you and letting your voice be heard."