Campaign Politics

So I was doing my usual reading of when I came across this ad. Now, I am all for making a statement but the one that is made by the above McCain ad seems a bit out of control. However, regardless of my personal political opinions, even I can see the benefits to having such a buzz-worthy ad floating around the internet. I mean I saw it, closed my browser, and then went back to look again. It really caught my attention. It seemed like an outrageous comment and I figured that it was really just a fake banner ad that was meant to cause trouble. But when I went on to research it I found out what the story behind it was. Castro did indeed call Obama "the most advanced candidate," though he has since criticized many of his plans. So that got me thinking that while the ad is a bit obnoxious, it does really work to get people thinking about what they want out of a leader (though I do wonder if other people would look to see what the whole story was behind it as I did). Regardless of anything, this isn't the first time McCain has run such ads. Below is another ad which was put out by the McCain camp looking to defame Obama. So my question is....Does campaigning ever cross a line? And when does an ad go from making the candidate look good to making the candidate look stupid?