In her rather unflattering review of Thomas Frank's The Wrecking Crew, a charged attack on the Republican's control of Washington, D.C., Times reviewer Michiko Kakutani not only decried the tone of the book (Frank was just too darn angry) but she complained that Frank sometimes didn't back up the factual claims found in his passages.
But as Jonathan Schwarz at A Tiny Revolution points out, Frank often used something called footnotes to back up the factual claims in his passages. Footnotes that Kakutani didn't always read.