Boehner also stated that sanctions would come quickly after a failed agreement.
Another way of looking at that statement is that Boehner said the GOP in Congress will do nothing to stop the agreement in the first place.
That's not new, they known that since Dec 2013.
The issue was never about whether or not there would be sanctions, everyone was in agreement on the sanctions if no agreement was reached.
The conflict arose in Dec 2013 when the neocon Republicans, led by Mark Kirk, and Liberal Interventionist democrats, led by Robert Menendez wanted to pre-emptively list, with a congressional act, the additional sanctions that congress would impose if and when the negotiations failed. The purpose was threaten Iran, and induce them to consent.
But those opposed to the pre-emptive sanction said that would only undermine the negotiations, and it would be better to wait until the negotiations fail before they apply negotiations.
In 2015, the issue of pre-emptive sanctions is moot because now the end of negotiations is close at hand.
Now the key legislation is Bob Corker's bill which requires congressional approval of any agreement that Obama may reach with Iran, which Obama will veto, so the question is whether or not there is 67 votes in the senate to override Obama's veto.
But if P5 plus one doesn't reach agreement with Iran, then Corker's bill will be moot.