Plagiarism daisy chain?

ThinkProgress has a post about how John McCain plagiarized from a speech by Admiral Timothy Ziemer, BUT the last entry is the following:

It appears that Ziemer's speech may have been plagiarized from McCain. According to the McCain campaign, the senator used these lines before Ziemer -- in 1995. We regret the error.

One thinks of Joni Mitchell:

And the seasons they go round and round
And the painted ponies go up and down
We're captive on the carousel of time
We can't return, we can only look behind
From where we came
And go round and round and round
In the circle game

IPBiz notes that the plagiarism-naming in the above is such fluff compared to some of the more serious
issues which have passed on by, like page 54 of Poshard's Ph.D. thesis.