People trying to persuade others to adopt their views are very likely to cite think-tank experts who agree with them. And the liberal lobbying group Americans for Democratic Action (their description of themselves) regularly grades politicians from 0 to 100 based on their votes on selected issues, with the most liberal members of Congress earning 100. Two researchers have combined these two disparate ideas to come up with a measure of media bias that doesn't depend on journalists' own perceptions of where they fit on the political spectrum, or on subjective judgments about the philosophical orientation of think tanks. Tim...