[raisetheroof]

While I agree with Will's overall assessment, this part is wrong: "In 1939, after a decade of frantic federal spending -- President Herbert Hoover...".

Hoover was president only until 1933. FDR was president in 1939.

[Kay]

When I read that sentence, I thought the same thing you did. But Gerge Will put in the “ — “ meaning that we should skip from the “..federal spending” to the end of the sentence. The words between the two “—” is an insert.

You are correct that FDR was president in 1939.