Dan Drezner says he understands why conservatives might not be crazy about the interim nuclear deal that Western nations cut with Iran over the weekend. But freaking out about it? That's just dumb:
Seriously, game this out. Let's assume you implacably oppose the negotiations going forward. If the deal holds up — and before you laugh, consider that Netanyahu is now describing the much-derided-at-the-time Syria deal as a "model" to follow — then you've undermined your reputation before the really big negotiations start. So whatever justified opposition you might have to such a deal will be largely discredited. On the other hand, if the deal falls apart — and there's a decent chance of that — then you'll get blamed for obstructionism for reflexively opposing it from the get-go.
Now say you announce that despite your reservations, you'll support the Obama administration's steps towards peace provided the necessary security guarantees are procured, etc. In this universe, if the deal falls through, it's on the Obama administration, and you get to shake your head sadly and cluck about how you should have known better than to trust them. If the deal succeeds but a comprehensive deal fails, that's also on the Obama administration, nothing has been lost, and you look like a sober statesman. Finally, if a comprehensive deal really is reached, you can oppose it then. Indeed, your opposition will be bolstered by the fact that you supported the interim negotiations, suggesting that you're not opposing diplomacy like a knee-jerk automaton.
Drezner asks at the end, "Am I missing anything?" Why yes, Dan, you are! Republicans are concerned with at least two meta-issues:
If a Republican supports the interim deal and it then falls apart, they're unmasked as a sucker, both for trusting the Iranians and for trusting Obama. If they support an interim deal and it produces a permanent deal, they've helped facilitate surrender to the enemy—for you can be sure that any permanent deal with Iran will be viewed as a sellout. The sad truth is that supporting the interim deal, even tentatively, is a lose-lose proposition for most Republican politicians these days. They don't care about you or me or the Beltway consensus. They care about the base. And the base has no interest in seeing Satan make a deal with the devil.