Semoochie:Yes, Wallace split the democratic vote. If he hadn't been there, Hubert Humphrey probably would've won and things might have been different. You have to wonder though, since Humphrey seemed to be such a nice guy, if he may have run into the same problems as Jimmy Carter, not being able to get things done because of a lack of cooperation from congress.
I think you have a point about The Carpenters. I don't remember anything about the photoshoot. It's conceivable that not enough people knew about it to affect their careers in a negative way. This doesn't change the way I feel about them. It's also possible that they didn't know anything about Watergate. It took awhile for the public to catch on after The Washington Post began to print the articles and The Post was an also-ran paper. The Washington Star was the main one before Watergate.
Wallace may have been a Southern Democrat before he went independent, but very few people who voted for him would have voted for Humphrey had Wallace not been on the ballot. Nixon was perceived as the more "law and order" candidate (a loaded term) and Humphrey, as part of Johnson's administration, was seen as having responsibility for the Civil Rights Act, which was not popular among Wallace voters.
As for the Carpenters...as Tomas Estefan noted (which prompted the picture), there are a group of people who considered their appearing with Nixon in an election year an indication that they had conservative political views, and that cost them. It didn't kill their careers, but it was one more factor in an image problem they had.
You may have forgotten, but the Washington Post didn't go it alone on Watergate---the New York Times and other publications were working hard to catch up to Woodward and Bernstein, whose work went national in a hurry...syndicated in most other cities around the country.
Finally, the Washington Star was the number one daily in D.C.----until 1961, when the Post passed it in circulation. What Watergate did for the Washington Post was to elevate it to a national newspaper---a legitimate rival to the New York Times.