Recurse you, Gray Baron

Diagramming party to action stations: NYT sentence off the port bow!

Some Democrats said that Mr. Obama must still demonstrate he would be a more effective president than Mr. McCain, and that he could unite the Democratic Party before its convention.*

Recursion is a lovely property that lets you hook clauses together almost indefinitely: This is the party that still must demonstrate that it loves the country that despairs over the troubles that submerged the banks that protested the crisis that arose last fall that destroyed the hops that enlivened the malt that lived in the house that Jack built. Collisions arise when you forget to mark the intersections correctly. What does our target sentence mean?

Some Democrats said that
[Mr. Obama must still demonstrate he would be a more effective president than Mr. McCain], and that [he could unite the Democratic Party before its convention.]

or

Some Democrats said that Mr. Obama must still demonstrate
[he would be a more effective president than Mr. McCain], and that [he could unite the Democratic Party before its convention.]

The second reading seems to make more intuitive sense (and judging from the online tweak, is what the paper meant).** But the first is what the original "grammar" says. The punctuation doesn't help; it appears to be our old friend the "ham, and eggs" comma, an irrelevant mark thrown into a compound of two because the writer can't think of anything else to do.

Moral: When you can't tell what a sentence means, out cutlasses pencils and board. Even if you're the Times.

* This is the sentence as it appears on page 15A of the national edn; the complementizer is moved around in the online version. Wanna guess where?
** The parallelism fault -- both subordinated clauses need the "that" -- is noted in most stylebooks, but it's still extremely common in news writing, especially AP's.