About halfway through, Buchanan attributes Ed Muskie's downfall in '72 to David Broder's story about Muskie breaking down in tears outside the Manchester Union Leader. This is presented as a rebuttal to Perlstein's attributing Muskie's loss, in part, to the "Canuck Letter." (Nixon's White House staff forged the Canuck Letter and sent it to the Union Leader in an effort to imply Muskie held a prejudice against his state's French-Canadian population.) That's misleading.
Undoubtedly, Broder's story had a devastating effect, but it couldn't have happened without the Canuck letter. Here's the relevant section of the '72 article:
With tears streaming down his face and his voice choked with emotion, Senator Edmund S. Muskie (D-Maine) stood in the snow outside the Manchester Union Leader this morning and accused its publisher of making vicious attacks on him and his wife, Jane.
The Democratic presidential candidate called publisher William Loeb "a gutless coward' for involving Mrs. Muskie in the campaign and said four times that Loeb had lied in charging that Muskie had condoned a slur on Americans of French-Canadian descent.
In defending his wife, Muskie broke down three times in as many minutes-- uttering a few words and then standing silent in the near blizzard, rubbing at his face, his shoulders heaving, while he attempted to regain his composure sufficiently to speak.
As should be clear from that passage, Muskie's "crying speech" took as its subject none other than the Canuck Letter. Some readers will certainly respond: So what? The guy cried! He wasn't fit to be President! Well, not so fast.
Broder has since written about this episode regretfully and at length:
In retrospect, though, there were a few problems with the Muskie story. First, it is unclear whether Muskie did cry. He insists he never shed the tears we thought we saw. Melting snow from his hat-less head filled his eyes, he said, and made him wipe his face. While admitting that exhaustion and emotion got the better of him that morning, the senator believes that he was damaged more by the press and television coverage of the event than by his own actions.
Second, it is now clear that the incident should have been placed in a different context: Muskie was victimized by the classic dirty trick that had been engineered by agents of the distant and detached President Nixon. The Loeb editorial that had brought Muskie out in the snowstorm had been based on a letter forged by a White House staff member intent on destroying Muskie's credibility. But we didn't know that and we didn't work hard enough to find out.
Muskie didn't necessarily cry. It could have been the snow. At least, Broder doesn't seem willing to stand by that aspect of the story.
Broder's retrospective is worth reading as an example of how an arbitrary act of political journalism can drastically alter the course of an election. (Broder thought Muskie was a hothead, and conformed his reporting to that view. For more on that aspect, see here.) I bring it up mainly to show that (if you watch the clip again) Barnicle and Buchanan are misleading the television audience in their defense of Nixon. Muskie's speech outside the Union Leader and the White House's effort at sabotage part of the same sequence of events; the latter rather clearly prompted the former.