You Want This Guy With The Nuclear Codes?

What is wrong with this guy? I know John McCain has a legendary temper (Tony Soprano-legendary), but you'd think that a person running for the highest office in the land would at least be able to keep his anger somewhat in check during the final Presidential debate. I thought at one point he was going to throw that Sharpie at Obama's head and challenge him to an Honor Du-El.
The creepy smirk, the million-blinks-an-hour pace he was setting, and the audible "heh's and uhh's" while Obama or the moderator was speaking were incredible. The sheer lack of respect, and the obvious mountain of disgust he feels towards Barack Obama, caused him to roll his eyes as Obama stated that the targeted murder of union leaders in Colombia was a reason he opposes the trade deal. Now, reasonable people can disagree on the merits of the US-Colombia Free Trade Agreement, but I think being dismissive of or emotionally ambivalent to an organized campaign to assassinate law-abiding citizens is not a quality that the Leader of the Free World should possess.
Tales around Washington go back decades of McCain's inability to control his temper- at staffers, at other Senators, at foreign emissaries, at the relatives of fellow Hanoi Hilton prisoners of war. A couple outbursts at like minded Republican Senators: "Fuck You", to John Cornyn, in a tense bipartisan meeting on comprehensive immigration reform; "Only an asshole would put together a budget like this", to Pete Domenici at a GOP budget meeting, who followed that remark with restraint, to which McCain retorted, "I wouldn't call you an asshole unless you really were an asshole"; and "No, (I'm not calling you stupid) I'm calling you a fucking jerk", to Chuck Grassley.
If this is how he treats his fellow Senate Republicans, people he most likely respects, how do you think he'd do in tense negotiations with Putin on non-proliferation of nuclear weapons, or with trying to diffuse another Pakistan-India nuclear standoff? This guy is a nut, a former Navy brat bully who hasn't stopped trying to intimidate people who disagree with him.
I hope Joe the Plumber was watching this debate, as it became clear that if old angry John McCain becomes President, Joe the Plumber won't have many shitters to unclog as he'll instigate World War III before the 2010 midterm elections.
Anyway, this guy is unstable, and I don't want him anywhere near the launch codes.