Wha? You got the definition right, but you didn't cite an example from the editorial to prove your point which was, apparently, that Hitch argued fallaciously. Just because Hitch criticized Romney, that's not an ad hominem attack. An ad hominem attack would look like this:

"Dinesh D'Souza says that Christianity ennobles humanity and has lead to the enlightenment of mankind and the establishment of western democracy, but D'Souza is a wonky pinhead and you can't believe anything that comes out of his mouth."