Michael Barone,
writing for
RealClearPolitics, about what the polls (or their absence) mean. He cites Jim Geraghty of
National Review Online as saying Democrats on Republican target lists haven't released poll results. Barone interprets this failure-to-release:
Most are conducting polls; many have reason to release favorable results if they're available. This looks like a case where the absence of evidence is evidence of absence.
I like that turn of phrase: "the absence of evidence is evidence of absence."