Clark was first in his class at West Point, won a Rhodes Scholarship, and studied (the "s" word) politics, philosophy and economics at Oxford. Similar to our Dear Leader, McCain was 5th from the bottom at Annapolis. Like our Dear Leader, that is a badge of honor for him, and he recently proudly professed that he did not know very much about economics. [Can we survive another 4 years of belief-based politics?].
Clark did not come from a privileged background with contacts in the Army. McCain got into Annapolis because his fathers were admirals. As he was working his way up the ladder in the Army, Clark received numerous letters highly commending his acumen and performance from commanding officers.
Clark became a 4-star General. McCain left the Navy because he was not going to be able to make Admiral. Incidentally, McCain also crashed several of his Navy planes when they were not being shot at.
Clark was Supreme Allied Commander of NATO--you know, one of the pesky little multinational things where hearing someone else's perspective occasionally comes in handy. McCain's insane temper tantrums at almost nothing--e.g., FoxNew's Morton Kondracke asking McCain if he would support an amendment directing a bit more NIH research for Parkinson's Disease, that made Kondracke to conclude that McCain was "not Presidential material", despite his prior admiration of him--are so frequent that they are no longer "news".
Clark knows that the al-Qaeda are Sunni, and Iran is a Shia theocracy. Without Joe Lieberman whispering sweet nothings into his ear, McCain does not. Oh yes, Clark also knows that Shia and Sunni have not had the greatest of relationships for, oh, say, centuries. McCain thinks it is, and has always been, all one big happy Islamist-terrorist family.
Clark opposed the Iraq invasion. McCain plumped for it. McCain said we would be greeted as liberators. Clark does not know just who the enemy is in Iraq, and what the definition of victory is. Neither does McCain. Clark not knowing leads him to doubt the wisdom of the continuing involvement of the US. McCain not knowing makes this, well, no different from just about everything else McCain espouses so why make an exception of Iraq.
Clark has been married to one woman his entire adult life. McCain dumped his wife who had been severely injured in a car accident, and had waited patiently for his return from Hanoi. Ronald Reagan and Nancy Reagan did not like McCain for doing that. McCain committed adultery with his current wife while he was still married to his ex-wife. He also received a marriage license before he was divorced--now, here was a man on a mission!
After decades of service in the Army, Clark retired with little money, and earned a few million himself. McCain dumped his injured first wife for an heiress, flies around in a private plane, owns 8-10 houses. Oh yes, incidentally, remember when McCain was working on campaign finance reform--guess what form of transportation is exempt from reporting? Yep, if you use your own private plane! One wonders how that got in there.....
Clark truly is an independent, a non-ideologue. He joined the Democratic party because of how bad Bush and the Republicans had become. McCain calls himself a proud conservative, and has already made multiple faustian bargains on judges, on taxes, and other matters. McCain voted with Bush 95% of the time.
When he ran himself for President, Clark proposed a major middle class tax cut, paid for by a small increase in tax rates on the top bracket. He has not wavered. When McCain was in the Senate, he opposed the Bush tax cuts on the grounds they were fiscally irresponsible and favored the rich; when he ran for President himself McCain wavered--he backs fiscally irresponsible taxcuts for the top bracket.
McCain has no experience in international diplomacy, and his first instinct in any confrontation is to escalate it--whether it is his own insane temper, or bombing Iran, or the in-your-face arrogance of power displayed by our Dear Leader. Clark, who has actually studied and operated in the world at large, displays a more nuanced approach.