McCain seems to frequently wake up on the other side of the bed...

There is much talk about John McCain's temper, as he is frequently known as "Senator Hothead" from numerous publications. He is also known for his famous quotes: "F*** you" (directed towards Texas Senator John Cornyn), "Only an a****** would put together a budget like this," (directed towards Senator Pete Domenici), and "I'm calling you a f****** jerk!" (directed towards Senator Chuck Grassley).  He has also been seen lashing out at his fellow citizens, as he called a high school student a jerk after he was claimed too old to be president (ABC News).   There are also numerous video clippings of McCain's 'freak outs'. Here are some examples:

Temper Tantrum 1

Temper Tantrum 2 (Where he makes a lady cry!)

Plus many other YouTube videos with examples, search "McCain Temper".

These videos also contain examples of McCain cursing excessively. 

Yet both John and Cindy McCain's reasoning for his temperament is simply because McCain feels so passionate and concerned for his country, and that many just happen to confuse McCain's strong passion for quick temperament. Many citizens of the US find his temer to be very crude and disrespectful, while others believe that McCain just represents the common man, and that his temper is equivalent to the average person (New York Times). 

I  guess it all depends on the citizen, whether they prefer the common man, who is  erratic and willing to freak out on anyone who comes in his way. Or a more calm and collected Barack Obama, who is willing to hold back such unnecessary 'freak outs'.