Kerry Claims Sarin Proof

We'll have to learn more about the quality of the samples and if UN confirms, but this just now via Politico.   Now full transcript.

Secretary of State John Kerry said Sunday that samples from first responders in Damascus have tested positive for signs of sarin gas exposure.

"Let me just add that this morning, a very important recent development, that in the last 24 hours, we have learned through samples that were provided to the United States that have now been tested from first responders in east Damascus and hair samples and blood samples have tested positive for signatures of sarin," Kerry said on NBC's "Meet the Press." "So, this case is building, and this case will build."

Kerry also said:  "The word 'slam-dunk' should be retired from the American national security issues."  Added he expects yes vote in Congress.  Update: Chris Wallace grills Kerry on Fox.

Note:   Ezra Klein on how the air assault would likely kill more civilians than the number who allegedly perished in the chem attack.