You can lead a Senator to water, but you cannot make him think. Benjamin Netanyahu’s bellicose bellyaching notwithstanding, getting Iran to give up its nuclear ambitions makes the world safer, is broadly popular with the American people, and is the crowning achievement of an American-led foreign policy in a messy, post-9/11 world. But if this good deal is to become a real deal, first Kerry and his boss must get it past the numbskulls they used to serve with in the United States Senate.

Let’s get something straight first: This is a good deal. Iran agrees to stop trying to build a nuke and to allow inspections and monitoring. In exchange, we lift only the sanctions that are related to their nuclear program (others stay in place) and we let them have their frozen bank accounts. What do we give up? Nothing.

This is what American leadership can achieve in the world. Compared to continuing sanctions and hoping they stop pursuing the bomb—or, worse yet, going to war against Iran—it’s pretty close to a best-case scenario.

Now the biggest obstacle to American leadership abroad is political obstruction in the Senate, because the most combustible material in Washington is a senator who feels like he’s not being treated like the most important person in the world. (See also: John McCain.)

The nuclear deal with Iran, the United States, and five of our allies in Europe is an executive agreement, not a treaty. It should not require Senate approval. That didn’t stop 47 Republican Senators from trying to torpedo the negotiations, a particularly odious example of devaluing the presidency and by extension our ability to lead in the world. And it’s also why the Senate has insisted on the right to review the Iran deal, potentially scuttling our biggest foreign policy victory since the Clinton years. But that’s just politics as usual in Washington now.

It’s no surprise that Republicans are against the Iran deal. I keep wanting Obama to extol the virtues of drinking water to see if congressional Republicans will die of thirst. The Republican presidential primary is exerting a tidal pull on this disloyal opposition that’s more partisan than patriotic. With Senators Rand Paul, Ted Cruz, and Lindsey Graham running for president from the senate, don’t expect an elevated debate coming out of this.

But how, then, can you explain the grandstanding coming from the Democrats in the Senate? It’s one thing to put politics ahead of country, as the Republicans are doing. It’s another to put ego before country. Taken as a whole, most of the objections coming from the Senate Democrats seem like cheap excuses to get on cable television.

Some Senate Democrats worry the deal endangers Israel, when in fact this makes Israel safer. Nothing short of all-out war with Iran will make Netanyahu happy—imagine Dick Cheney with better hair—but he’s not our president.

Other Democratic Senators are making a show of demanding “intrusive” inspections. These have always been a core component in the negotiations. It’s like they were insisting that water contain hydrogen and oxygen molecules in every atom just to hear their voices booming in the senate chamber just like real statesmen.

The fact is that the Senate isn’t just obstructing the President but also the public. A nuclear deal with Iran is extraordinarily popular with the American people. A CNN/ORC poll from last March found that 68 percent of Americans favor “direct diplomatic negotiations between the U.S. and Iran in an attempt to prevent Iran from developing nuclear weapons.” And ABC News/Washington Post poll around the same time found similar levels of support.

It shouldn’t take political courage to do what is popular with huge majorities of the American people. First, though, our senators will have to remember that if they want the United States to lead in a more peaceful and prosperous world, they’ll have to remember that there are some things more important than hearing themselves talk on cable news. We’ve got enough problems in the world without scuttling our last good chance at keeping Iran from getting nuclear weapons. The Senate needs to get out of the way and take the win.