Strictly speaking, treaties, which this is, must be approved by the Senate, right?
Also, I believe after the Obama Iran deal, congress passed a law specifically targeting deals with Iran, saying they need to at least be presented to congress before being signed... because Obama didn't do that with his horrible deal.
I just can't wrap my head around why the democrat party wants Iran to have nukes. I think I know why, but if so, they're a worse shitshow over there than even I thought they were.