Same type of question: was there ever popular left-wing AM radio? Like a counterpart to Rush Limbaugh? Like highly emotive and monetized liberal (in the American sense) talk radio?
Interesting, I wasn't aware of that. But I don't think it qualifies as "popular". The Wikipedia page says it lost around $10mil a year and then folded after 6 years in a mess of debts.
At around the same time, Rush Limbaugh's salary was $30mil+.