Since I last wrote about it, Aetna’s withdrawal from the Obamacare exchanges has ginned up even more drama.

Jeff Young and Jonathan Cohn of the Huffington Post published a letter in which Aetna told the Justice Department that it would reduce its exchange participation unless Justice allowed the merger with Humana to go through. This has naturally triggered a firestorm of accusations about “extortion” and renewed calls for a public option that can protect people against the threat of insurance-less insurance exchanges.

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