The true nature of the debate over the Iran nuclear deal announced last month is slowly coming into focus. Those who favor it are are backed by dozens of nuclear scientists and arms control experts, while opponents consist almost exclusively of bellwether politicians mugging for the camera and playing into the fears of the constituents they have whipped into a terrified frenzy.

That’s where the ever intensifying debate surrounding the nuclear agreement between the United States and Iran now sits, as a furious lobbying campaign – estimated to cost upwards of $40m – tries to buy enough votes in Congress to override the president and scuttle the historic deal.

The biggest news about the deal last week should have been the fact that 29 of what the New York Times called “some of the world’s most knowledgeable experts in the fields of nuclear weapons and arms control” came out in favor of it. The scientists agreed that the deal has “more stringent constraints than any previously negotiated nonproliferation framework.”

Instead, Senator Chuck Schumer, who is poised to be the incoming Senate Democratic leader, got far more press by coming out against it after reportedly being pressured by pro-Netanyahu lobbyists for weeks. Nonproliferation expert Jeffrey Lewis, who goes by @ArmsControlWonk on Twitter, skewered Schumer in Foreign Policy for his disingenuous and misleading reasoning for opposing the deal, explaining that Schumer got “got the facts all wrong” and “came across a bit like your crazy uncle who gets his opinions from talk radio and wants to set you straight at Thanksgiving.”

It’s entirely predictable, yet demoralizing, that actual experts are being largely ignored in the public debate over the opinions of politicians who are being fed talking points by lobbyists. Even Israeli prime minister Benjamin Netanyahu has been accused of silencing Iranian experts in his own country’s intelligence agencies who are in favor of the deal.

Fortunately, it doesn’t look like Schumer and pro-Netanyahu lobbyists are taking enough Democrats with them to submarine the deal. Since his announcement, several of his party members have come out in favor of the deal, signaling that just maybe diplomacy and peace may rule the day for once.

However, Republican presidential candidates, which there are enough of to field a football team at this point, are beating the war drum constantly, with some of them ignorantly promising they’ll cancel the deal on “day one.” What they don’t tell anyone is what actual consequences that will have, either because they haven’t thought ahead to day two, or they are purposefully lying – it’s unclear.

As former Clinton national security adviser Sandy Berger convincingly explains in Politico Magazine last week, scuttling the deal now or when the next president is inaugurated will probably be the worst of all worlds. It would give the Iranians the perfect ploy to play victim on the world stage, none of the sanctions from the rest of the world would be enforced and Iran wouldn’t have to abide by any of the rules of the agreement, only the ones which they could pick and choose. Far from pushing the president into “a better deal,” like they claim, Republicans and others are instead pulling the entire rug out from under him.

Everyone seems to be pretending this is just a deal between the US and Iran, when it actually involves Russia and China and Europe, and no matter what the US does, the rest of the world is going to end sanctions against Iran. So it’s really just a question of whether the US wishes to make economic enemies out of its European allies, and whether no deal is better than this one.

All of this is why it was so satisfying to see President Obama publicly defend the agreement with the contempt the deal’s critics deserve. In a blistering speech and interviews that followed, he accused Republicans of not reading the deal, wanting war with Iran and saying hard-liners in Iran were “making common cause with the Republican caucus.”

The Republican reaction was both amusing and telling. How dare he call us out like that, was apparently their response. Senate Majority leader Mitch McConnell cried to reporters that he was “especially insulted” and said Obama “way over the line of civil discourse.” This is particularly rich given that two of McConnell’s own party’s presidential candidates had separately claimed that Obama was marching Israelis “to the door of the oven” and that Obama would be the world’s “leading financier of radical Islamic terrorism” if the bill passed. What discourse!

I, for one, really enjoy the new no-holds-barred version of Obama, who lately has been going off on not only the Iran deal, but criminal justice, the climate and other issues. It’s about time he stops worrying about what Republicans think of him and tells the American public the blunt truth.