A little more on Reagan and Ford...
“Campaigning in Florida that March, Ronald Reagan broke the 11th Commandment and attacked Gerald Ford. He accused Ford, who had then been president just 19 months, of presiding over “the collapse of American will and the retreat of American power,” and said Ford “must be held accountable to history for allowing this to happen.” He said Ford lacked “vision,” that he found it “difficult” to trust his leadership. He accused the president of favoring “pre-emptive concessions” in talks with the Soviet Union, and said, “I fear for my country when I see White House indifference to the decline in our military position.””
Not exactly calling him a ‘liar’, but an attack none the less.
As I said, Reagan attacked the current policies of his oppenents. He didn’t accuse them of lying when they agreed with him, based on positions they held over a decade before. As I recall George H.W. Bush changed his position on abortion only after Reagan picked him for VP, but he held it staunchly ever since.
I’m not crazy about any of these guys, but one of them will almost certainly be the nominee. Engaging in personal attacks will only help Hillary, Obama or Edwards in the long run. I would rather have a half-hearted ally in the presidency than a determined enemy.