Why does Gingrich keep calling Mitt Romney "timid"?

He even uses the word "timid" as a noun.

It seems like the creators of the ad decided to play around with the name "Mitt," so they flipped it over to get "tiM," flopped it back so it's "Mitt" again, then put them side by side to get "tiM-Mitt," which sounds like "timid."

It some kind of palindrome!

And then what would happen if Mitt picked Tim Pawlenty as his VP? The brains of poets will explode. But what kind of an ear for poetry do we average Americans have? Perhaps it doesn't matter whether you notice. It's harder to defend against the subliminal effects. The words seep directly into your emotions. You get these uneasy feelings about the candidate, and you don't know why.

And then again, we do hear poetry in the language of politics: I like Ike... tricky Dick.... Even when you hear it and you can defend against it, you're hooked. You do like Ike. And Dick Nixon is tricky.