There are many countries that have expressed their concerns with this deal. Iran is an aggressively Shi'a Muslim nation. The Gulf States - Saudi Arabia, Kuwait, Bahrain, Qatar, UAE, and Oman are all under the control of Sunni Muslim governments and, they are all concerned with the growing Shi'a/Iranian meddling in other country's internal affairs.
An unnamed Saudi Arabian leader was quoted over the weekend by CNN International as saying:
"Many in Saudi Arabia worry that Iran is not being sincere, and the worry during the negotiations was that any deal reached would mean Iran would widen their influence in the region -- in countries like Lebanon and Bahrain -- and become a bigger threat."
Israel was instantaneously opposed. Prime Minister Benjamin Netanyahu was out quickly with a statement saying that this wasn't so much an historic deal as an "historic mistake." The head of Israel's intelligence services said it "is more likely to bring Iran closer to having a bomb."
Republicans in Congress were quick to respond. One of the few Members who (a) knows what he is talking about and (b) is not noted for running over staff to get in front of a camera is House Intelligence Committee Chair, Mike Rogers (R-MI) said on CNN's Sunday show that the agreement "rewarded [Iran's] very bad and dangerous behavior."
But Congressional Republicans were not alone. A member of the Democratic Senate Leadership, Sen. Charles Schumer (D-NY) threw a pail of water over the whole sanctions thing.
"As for additional sanctions, this disproportionality of this agreement makes it more likely that Democrats and Republicans will join together and pass additional sanctions when we return in December. I intend to discuss that possibility with my colleagues."
That's the way Senators sometimes speak. You just smile and nod and move on.
This is a high risk activity for Democrats. If the deal falls apart in six months - next May - that may add to, or even replace, Dems running for office six months after that in the Mid Term Elections.
Maybe it will work. I hope it does.