Not attempting to be political. Just analysing the strategic implications.
If the MoU is even close to what has been rumoured, this will significantly weaken the U.S. President's position during the midterms and practically guarantee a fully hostile Congress. This will significantly tie the hands of the United States. Not fully, as the President has quite a lot of latitude for military action. But in the face of a hostile government that has promised to do everything it can to stop the President, this will play into Iran's hand. Which is what they are hoping for.
Once again, the U.S. has snatched defeat from the jaws of victory.