I love that phrase, particularly when I see it in this context:
Tight Massachusetts race alarms California Dems
“For Boxer, a favorite Republican target, a GOP win in Massachusetts would be a particularly dark sign representing “not just the canary in the coal mine,” said Wade Randlett, a leading Silicon Valley fundraiser for Obama. “It’s the flock of dead ravens landing on the lawn.”
Go read it all, this is way down in the article in the San Francisco Chronicle.