What's the Kennection? #26

Whose billion-selling 1964 book included sayings like "Political power grows out of the barrel of a gun"?

What product's famous formula is based on a secret flavor ingredient called Merchandise 7X?

What music superstar had the #1 country hit in America, "Way Down," the week of his death on August 16, 1977?

Who converted to Judaism in 1956 to marry playwright Arthur Miller?

What food has used the slogan "Mmm mmm good" in its ads for over eighty years?

What's the "Kennection"?