When last we saw our intrepid heroes, the approaching wave of baby-boomers was threatening to overwhelm OASDI, and hard-working Polish farmers had the CAP at the point of several rusty pitchforks (oh, the tetanus!). What strikes me in the comparison of the two is the response to the crisis in each. Certainly, the fatal flaws in these programs have existed from their inception (since they lie in that very inception). Both, however, have recently faced the need for reform from an impending, irresistible, and disastrous increase in cost. But reform has occurred in only one of these cases.

Now, there are lots of caveats to the comparison, but let me first make the comparison. In response to what were likely to be astronomical increases in the cost of the CAP, the EU managed to reform it. Of course, they had more than one option—they could have abolished it, they could have lowered the target prices (the price level they sought to maintain through intervention), or they could have made agricultural subsidy independent of production (“decoupling”).
In the event, they chose the latter path, which is hardly surprising. The first would have put large numbers of angry French farmers on the streets of Brussels with torches in one hand and scathing glances filled with existential ennui in the other. It likely would have been unpopular with the newly acceding countries, as well, since for many of those countries this represented one of the benefits of membership. The second option would have angered only farmers in the current countries, and while consumers would have benefited, concentrated costs and dispersed benefits don’t make for good policy in a democracy (works great in authoritarian systems, though).
The least politically costly decision was, in fact, the one they made—keep spending what we are now, but make sure the amount doesn’t increase in the future. Current farmers aren’t happy, because the money has to be spread a little further around, but neither are they outraged. Similarly, acceding farmers aren’t happy, because they will miss the windfall they anticipated under the CAP, but neither are they outraged at getting nothing. And the EU got to remove the connection to production that was causing the costs to balloon.
Social Security, on the other hand, remains mired in its situation. Certainly, Congress could eliminate the program or reduce the payments, though they’d have a host of knitting-needle-wielding (say that five times fast) grannies after them, with no great thanks from the young whippersnappers who benefit. There’s a reason it’s called “the third rail of American politics.” But Congress could decouple it from earnings, and redirect payments to those of lowest means. And they haven’t.
Now there are certainly differences between the CAP and OASDI. Scale is one of them—OASDI involves roughly 10 times the amount of money. That could work two ways. On the one hand, perhaps it means more to those who receive it (though I doubt it—that probably reflects the scale of those receiving payments), which makes it more difficult to alter. To borrow from Scotland’s poet-genius, Mark Knopfler, no one wants to crash the ambulance.
On the other hand, that would seem to make reform more pressing. And perhaps that indicates the difference—timeframe. CAP reform arrived at its critical point, and Social Security will, too. One could argue that the EU put off reform until the last possible moment—and since Poland has already acceded, but the baby boomers have retired yet, Social Security hasn’t reached the last possible moment yet. Call it the Candide gambit: it’ll be okay by the time we get there.
Nevertheless, I can’t help but think that part of the reason the EU successfully reformed its boondoggle, while the U.S. has not, is the presence of indirect democracy in Europe. The people who had to answer to the farmers could use the EU as the scapegoat, whereas Congress…well, they usually blame the President, who blames them right back. That is, there’s a political buck that gets passed. Neither Congress nor the President wants the buck to explode while they’re holding it.
Indirect democracy, or at least some role for it (as in the Senate before the 17th Amendment), allows someone who doesn’t have to face voters to bear the brunt of their electoral wrath. And that, sometimes, is what allows politicians to do the right, rather than the expedient, thing.