It appears to me that the treasonous letter sent by 47 recalcitrant Senators was part of a two pronged attempt to derail the Policy course decided by our Democratically elected President Obama.
The other prong of this classic "Hammer and Tong" operation was the invitation [without notification of the POTUS] to Netanyahu to come the Congress and sandbag the President...Unnnbelievable treachery ....NONE DARE CALL IT TREASON
Yes, how dare they point out to the Iranians that any agreement with Obama they reach will be meaningless because they probably won't lift the sanctions.
It's bad form, because it tells the other six nations we aren't negotiating in good faith. But frankly, guy, if Obama just wants a treaty so he can have a treaty, that's kind of silly.