I could not agree more with your assessment of both the politics and the substance of Limbaugh's latest descent into tastelessness. But I argue that the pathogenesis of such behavior is intimately linked to the loss of the influence of moderates and the ascent of the most right wing elements of the GOP. I can understand your contempt for the likes of Ryan Lizza given your politics, but look at who else is making the same point about the long term hazards of the GOPs continued obsession with marginalizing itself.
It isn't good for the country to have one of its major political parties controlled by crackpots. This is true for both parties And while such lurches in one one direction or the other are inevitably corrected by devastating losses at the polls, the country suffers.