From the Guardian:
Carter also notes there's a cautionary moral hidden in Senator Clinton's appeal to the LBJ presidency. In coordinating research his son had lined up for a study of the Johnson presidency and the civil rights movement, Carter says, "I was going through all these transcripts of LBJ's White House tapes. And you know, he was truly committed, there was a real passion about this thing from LBJ. But as the years go by, he gets more and more angry when he has conflicts with black leaders. Because he's developed this view that he's made these sacrifices on their behalf - and by God, he thinks, 'They're mine. I'm entitled to these people. What do they mean by not being grateful to me?' "
King grew increasingly disappointed with Johnson, too -- especially about Vietnam. The price he paid for the Civil Rights Act of 1964 was to keep his criticism of Johnson's war policy quiet, until finally enough was enough. Which begs the question -- why in the world would any political candidate in the middle of a quagmire like this one, especially a Democrat, want to identify with Johnson?