Transcript for Watergate: Inside the scandal that took down a presidency
It was a political scandal that changed our country forever. Beginning with the break-in at democratic national headquarters in the watergate office complex. Ending in the resignation of president Richard Nixon. Tonight on the eve of the 45th anniversary of the watergate break-in we take an in-depth look at the events that led to his downfall. The president is going to address the nation and presumably announce his resignation in a half hour from now. People will be at television sets and radios tonight to hear what the president has to say. This is the political crime story of the century. In just a moment now the president of the United States will begin his speech, perhaps his last speech from the white house. He always saw enemies. He always saw people in the shadows. And his motto, I believe, was, "Do unto others before they have a chance to do unto you." That's enough. There was an obsession with leaks. You don't blame the leaks when facts come out that are showing wrongdoing. No, no, there will be no picture. This is the funny thing. Had it not been for watergate, I think this man could have gone down in history as one of the more significant presidents in the history of this country. Out. We were witnessing the implosion of an American presidency. The president has taken his place at the table in the white house where he's going to speak. Here now the next view will be the president of the united States. I have never been a quitter. To leave office before my term is completed is abhorrent to every instinct in my body. But as president, I must put the interests of America first. Therefore, I shall resign the presidency effective at noon tomorrow. Reporter: It was the scandal that took down a president. A plot of lies, Espe noun, and secret dealing that shattered how the nation viewed the presidency and the truth. It all started here, the now-infamous watergate office building, police were called to investigate a strange break-in. I was a sergeant assigned to, people called us the bum squad. What I looked like in 1972 was a junior Charles Manson. George town, Friday night going into Saturday, is always crazy back then. June 17th, 1972, there was a break-in at the democratic national committee's headquarters in the watergate office complex. This was the start of what would be the political crime of the century. Reporter: At the center of it all were two men, G. Gordon liddi, ex-fbi agent hired by president Nixon's campaign to run covert operations. He recruited James Mccord, security chief of the committee to re-elect the president. The plan was to get negative information about the potential nominee of the democratic party. How are you going to get the negative information? A lot of people would say, breaking into the democratic national committee was way out, off the charts. Yes, but not that far off. Mccord would go into the watergate building and put in tapes in the door. It was taped so it would not lock. The hero of that night was a man named frank wills. Frank wills was the security guard at the watergate office building. You found the door taped once and you took the tape off, then you found it taped the second time. It was something that told me that, you should check, not only check the door, but call the police. About 1:52 in the morning the call comes out for alleged burglary at the watergate hotel. I just kind of blinked my eyes, yeah, we'll take the call. I had on an old fogey golf cap, like a t-shirt underneath, trying to give me the image I wasn't a police officer. If a uniformed car had answered that call, it could have been a whole different ball game. There's a lookout. Alfred Baldwin was supposed to warn the burglars if there's trouble. The police unit that responds to the call, they're not dressed like police officers. Baldwin doesn't even notice them. Our adrenaline is pumping. We get to this room here. I kick the door open. I pulled my revolver. Reporter: Baldwin was supposed to be the lookout across the street. He was watching a show called "Attack of the puppet people." By the time Alfred Baldwin had notified them, it was too late. And they had to run and hide like rats. We're rolling down this hallway checking the offices on both sides of the hallways. Making sure nobody's hiding from behind us. I was startled by an arm hitting next to the glass on the partition. It scared the living ba Jesus out of me. "Come out with your hands up or I'm going to blow your head off." Ten hands came up and came out and that's where the arrests occurred. The five burglars arrested inside the DNC, mcco, barker, Sturgis, Martinez, Gonzalez. This was not your Normal, typical burglary. There was bugging devices, tear gas pens, many rolls of film, locksmith tools, thousands of dollars in 100-dollar bills consecutively ordered. Who goes into the democratic national committee looking for money? Or looking for jewels? No, you go there looking for political information. And who wants that? Your opponent, naturally. People weren't saying, oh my god this is clearly going to implicate Richard Nixon. It seemed bizarre. It would take some enterprising young journalists to ferret out the importance of the story. Woodward and Bernstein were assigned to this burglary as a matter of routine. Editors said, we got this strange burglary. They were young reporters trying to make their way up the ladder in the Washington post. When you talk about the people who made a difference when it came to watergate, you talk about Bob Woodward and Carl Bernstein. They sent me to the courthouse where the five burglars caught in the democratic headquarters were being arraigned. The judge asked the leader, James Mccord, where did you work? Mccord went, CIA. It was stunning. And they discovered that Mccord was a security chief for the committee to re-elect the president. Well, okay, folks. This was a political break-in. There was a notebook belonging to one of the burglars that had the name in it, H. Hunt, W. House. It turned out to be Howard hunt, who had worked for the CIA, who had been hired at the white house really to undertake dirty tricks. You knew that this smoke that was billowing up from the oval office, there had to be fire there. It's like the Dylan song, it don't take a weatherman to know which way the wind blows. Presidential increase secretary Ron zoeggeler called it a third-rate burglary attempt and said it was nothing the president would ever be concerned with. Richard Nixon is obstructing justice from the begin. What would be known as the smoking gun was when he approves a plan to use the CIA to blunt an FBI investigation into the money that the burglars had. It's clear in the conversation it's being done for political purposes basically to save the skin of the white house. The president says he approves it. Woodward and Bernstein had scores of sources. But there was one source that was special. A guy really high up. He was known as "Deep throat." We would learn years later that deep throat was mark felt. Number two at the FBI. He was in the perfect position to understand what was coming into the investigation, as well as what he could observe maybe from above the investigation. I want to talk about watergate. We're not going to talk about that subject. "All the president's men" created a sense of dwaeanger. Constantly risking thing busy trying to find out the truth. You can trust me, you know that. The other thing the movie did was create that expression, "Follow the money." Just follow money. And put it into American culture. Deep throat made it clear that the money was important, that there was a trail to follow. And Carl established that a $25,000 check had actually gone into the bank account of one of the watergate burglars. The $25,000 check linked contributions to president Nixon's re-election campaign to the slush fund used to pay the burglars who broke into the watergate office complex. I said, oh my god. This now establishes an undeniable connection between the committee for Nixon's re-election and the burglars. John Mitchell was the attorney general. A Nixon loyalist. The highest law enforcement officer in America controlled the secret fun that paid for undercover activities against Nixon's political opponents. Bradley said, they're about to call the attorney general of the United States a crook, there's never been a story like this in our history. And we took a deep breath and said, yeah. ABC news has projected that Richard Nixon has, in fact, been re-elected to the presidency, to a second term. The question now I suppose is how big will Mr. Nixon win? It was a giant landslide. There was virtually no reaction to the stories we did. And it was a way of saying, watergate? Who cares? What ever happened to watergate? I don't know, I don't know, apparently nothing. They've got a trial of the accused in that case. And that's going to be tried in due course. And I think that's probably the end of the story.
This transcript has been automatically generated and may not be 100% accurate.