nursery rhyme in chrysalis

So I'm reading Pepys's entry for 20 Jan, and the annotation expanding on the Thing with General Monk has this doggerel:

"Monk under a hood, not well understood,
The City pull in their horns;
The Speaker is out, and sick of the gout,
And the Parliament sit upon thorns.”
--Rugge's 'Diurnal.'--B."

Dunno who Rugge is, or what his "Diurnal" might be, or what "B" is supposed to mean (I said I was out of period here), but this did make me, for the first time, properly understand how political jingles turned into nursery rhymes. I mean, yes, I understood intellectually that it happened, but it was one of those things I knew without actually being able to make sense of. But now I get it.

And 'cause this is the kind of geek I am, right at the moment, I'm in love with this, with the pun on monkshood and the image of London as a snail, and that fabulous last line: "And the Parliament sit upon thorns." (Fantastic! says Elijah Wood in the back of my head.) It doesn't take much to make me happy (first rule of surviving grad school: be self-entertaining and easily amused), but this is an unexpected pick-me-up at 7:30 a.m. Which I needed.

Now, what I want to know is, when and how did our culture lose this ability? Why don't we get nasty little jingles about Dubya? 'Cause, frankly, I think our political system would be the better for a healthy dose of doggerel.

And, just because, here's my other favorite political jingle that didn't make it into Mother Goose:

The Cat, the Rat, and Lovell our Dog
Ruled all England under a Hog.