When conservative talk-radio icon Rush Limbaugh decided to record a series of public service announcements for the Humane Society of the United States, many animal lovers on both sides of the political aisle applauded. After all, the topics Limbaugh spoke about in the PSAs, like opposing dogfighting, hardly seemed controversial. "Opposition to cruelty and the embrace of the human-animal bond are universal values," Humane Society president Wayne Pacelle wrote, adding that his group's aims were "in step with those of all good people" regardless of political affiliation. But a coalition of 28 hunters' rights groups are furious with Limbaugh for...