AP reported "The denunciation of a sitting president was unprecedented for Carter, a biographer said." That biographer was Douglas Brinkley, who wrote a very favorable book on Carter's post-presidency years. But the tone doesn't sound all that different from Carter's 2004 speech to the Democrat convention, when he kvetched that all the post-9/11 good will "has been squandered by a virtually unbroken series of mistakes and miscalculations."
In an interview with the Arkansas Democrat-Gazette, Carter proclaimed "I think as far as the adverse impact on the nation around the world, this administration has been the worst in history...The overt reversal of America's basic values as expressed by previous administrations...has been the most disturbing to me."
Contentions, the blog of Commentary magazine, gets it right:
Speaking of the “worst in history,” there can be little doubt that Jimmy Carter is himself Our Worst Ex-President — which is the title of a comprehensive, timely, and utterly devastating essay by Josh Muravchik that COMMENTARY published in February.
What explains Carter’s own abominable conduct? “Ever since his presidency,” writes Muravchik, “there has been a wide gap between Carter’s estimation of himself and the esteem in which other Americans hold him.”