The Republican letter to Iran, signed by 47 senators, is all about US policy toward Iran: it's meant to undermine the Obama administration's effort to make a deal with Iran over its nuclear program, which many Republicans oppose.
But the letter is more than that. It's also a deeply revealing document that shows the future of the Republican Party. It demonstrates, in very clear terms, that Iran has risen to the top of conservatives' grievances with Obama's foreign policy. As the 2016 campaign heats up, expect this to manifest in a big way.
How Iran became the top foreign policy issue on the right
Since the very beginning of the Obama era, Republican politics have been defined by opposition to Obama's core policy priorities. This is often true with parties out of power. But increasing political polarization — the sorting of liberals into the Democratic Party and conservatives into the GOP — made Republican opposition especially stiff.
Until now, Republicans had refrained from aggressively undermining Obama's foreign policy in the way they had attacked his domestic initiatives. The Iran letter, organized by Senator Tom Cotton, crosses that line. Senate Republicans have moved from mere opposition to Obama's foreign policy to outright sabotage — an escalation that, in their eyes, is merited by the gravity of the Iran situation. The letter tells the Iranians that any deal on its nuclear program wouldn't be binding law, implying that a future Republican president or Congress might alter or break it.
To understand the Republicans' escalation, you need to understand the special role Iran has come to occupy in conservative foreign policy thinking. Iran isn't just a foreign policy issue on the right; it's the foreign policy issue.
It's now conventional wisdom on much of the right that Obama's foreign policy is actively empowering Iran. This fear goes well beyond the nuclear deal. The president's refusal to intervene more aggressively against Syrian President Bashar al-Assad, an Iranian ally, is seen as empowering Iran. Many of the Iraqi ground troops Obama is relying on to fight ISIS are Shia militias who either have close ties with Iran or are its direct proxies. The Shia Houthis, who recently seized control of Yemen's government, are counted as Iranian allies.
Iran, then, provides a unified theory of Obama's foreign policy failure in the Middle East. Because Obama wants to cooperate with Iran rather than confront it, conservatives argue, he's allowing an expansionist, anti-American, terrorist-supporting government to rise as regional hegemon.
The Iran-as-Great-Satan narrative pushes all of the conservative movement's major buttons: it casts Obama as dictator-appeasing and weak in the face of an aggressive regime. It's also grounded in strong evidence that Iran is ascendant in the Middle East (though conservatives often ignore that Iran's rise is in many ways a product of the 2003 Iraq invasion, among other factors).
When you understand this narrative, the letter — and the fact that 47 out of 54 Senate Republicans signed it — makes a lot more sense.
Republicans think Obama is making a world-historical error; his nuclear negotiations and response to the ISIS crisis are empowering an actor that, according to Sen. John McCain, is even more worrying than ISIS. That's why the two most brazen attempts to undermine Obama's foreign policy — Cotton's letter and the backroom invitation to Israeli Prime Minister Benjamin Netanyahu to address Congress in support of new sanctions on Iran — have come on the Iranian nuclear negotiations.
How the Iran issue will shape 2016
Sen. Cotton's letter was signed by the three most important senators in the 2016 campaign: Marco Rubio, Ted Cruz, and the normally dovish Rand Paul. Governor Bobby Jindal, also a potential 2016 candidate, has come out swinging in support of the letter:
Anyone thinking of running for Prez, on both sides, should sign on to the letter to make clear that Iran is negotiating w/ lame duck Prez.— Gov. Bobby Jindal (@BobbyJindal) March 10, 2015
This positioning makes political sense. These candidates are all competing to make themselves acceptable to the Republican donors and activists who play a huge role in determining primaries. Many of these influentials, like casino magnate Sheldon Adelson, take a pretty hawkish line on Iran. Failing to back the Cotton letter would be a black mark in their book.
This creates incentives for a race to the right on Iran policy. Given that Iran is enemy no. 1 right now on the hawkish right, the more aggressive line a candidate takes (perhaps short of openly advocating war), the more of a political advantage he'll have. That's why even the dovish Paul, who actually supports negotiating with Tehran on nukes, would sign on to Cotton's letter: for him, it's a way of seeming more aggressive on Iran without having to change his stated policy position.
And don't expect the Iran rhetoric to end anytime soon. If Obama strikes a deal with Iran by the March deadline, you can be sure that Republicans will slam it for being too generous to the Iranians. If he doesn't, the nuclear program will still be an open issue. Moreover, Iran will continue to meddle in Iraq, Syria, Lebanon, Yemen, and elsewhere — creating fertile ground for the conservative attack line.
The Republican policy consensus, then, is pushing the 2016 candidates to the hawkish right on Iran. Politically, Sen. Cotton's letter is an ingenious way of accelerating that process.