The definition of senile:
of, or relating to old age; exhibiting the deterioration in mind and body often accompanying old age; doddering
en.wiktionary.org/wiki/senile

However...
"Smears often consist of ad hominem attacks in the form of unverifiable rumors and are often distortions, half-truths, or even outright lies; smear campaigns are often propagated by gossip spreading. Even when the facts behind a smear are shown to lack proper foundation, the tactic is often effective because the target's reputation is tarnished before the truth is known."
http://en.wikipedia.org/wiki/Smear_campaign

I think that although calling McCain senile is an ad hominem attack, it is verifiable. He is old, he exhibits the deterioration of mind and body that accompanies old age--for example, he forgets important details and even what he says:
http://www.youtube.com/watch?v=GEtZlR3zp4c&eurl=http://www.bleedingheart...

So, is Liberaliconoclast smearing McCain by calling him senile?
I think he's not being nice, especially the way he calls him senile. But I don't think it's a stretch to say McCain is showing symptoms of senility.

"Every gun that is made, every warship launched, every rocket fired signifies in the final sense, a theft from those who hunger and are not fed, those who are cold and are not clothed." Dwight Eisenhower