Andrew Sullivan deems this his "Quote of the Day":
"Politics turns into virtue what religions often see as a vice—the fact that we do not all think alike, that we have conflicting interests, that we see the world through different eyes. Politics knows what religion sometimes forgets, that the imposition of truth by force and the suppression of dissent by power is the end of freedom and a denial of human dignity. When religion enters the political arena, we should repeat daily Bunyan's famous words: 'Then I saw that there was a way to Hell, even from the gates of Heaven.'" - Rabbi Sir Jonathan Sacks, reminding us of something vital that today's Republican leadership has forgotten.This typifies why I increasingly find Andrew's blog unuseful for obtaining insight on important matters; he views nearly everything through spectacles colored by the gay-marriage issue, and propounds everything through that narrowed vision.
Had Andrew actually thought about this for over a fraction of a second, he would no doubt realize how absolutely idiotic a statement Rabbi Sacks has made here. He'd realize that politics is (indeed) all about imposing truth by force. That is, in fact, the only thing it's good for; we want, for example, slavery to be prohibited, by force when and if necessary. The best outcome for which we can hope is that the sphere of the political world be severely limited to the classical liberal vision.
The institution that does the best job of satisfying varying values, interests, and modes of thought is neither politics nor religion, but the free market, of course. Rabbi Sacks and Andrew do not see fit to mention that. Politics, by its nature, is a one-brand, one-size-fits-all, top-down monopoly. Political winners don't just decide for their customers; they decide for everyone under their domain; this is irrespective of their (hopefully democratic) methods or (hopefully benign, if not noble) motives.
Andrew is peeved at Republicans because at least some, maybe most, of their opposition to his pet issue comes from folks operating under (presumably) religious motives. And he sees Rabbi Sacks' essay as another hammer he can use to pound that particular nail. Fine. But you can make your argument about that without erroneous generalization.
Illiberal incursions into modern American politics are bad, not because they're religiously-motivated, but simply because they're illiberal. The primary mass-murdering regimes in recent history have (of course) been illiberal, but also pretty much irreligious. While Islamic religious fundamentalism is clearly dangerous, that's not a lesson Republicans particularly need to learn, and it's clearly not the lesson Rabbi Sacks is trying to teach.
The problems with a simplistic focus on banning religious insights from the political sphere are the ones you might expect. You throw out good ideas and alienate possible allies, simply because of their beliefs and motives; you throw the door open to bad ideas simply because they've passed your secular litmus test. Why?
That said, parts of Rabbi Sacks' article contain good (if pedestrian) arguments for classical liberal democracy. His off-kilter focus and inability to make relevant distinctions, however, are fatal flaws. There are at least a few thousand better explications of the brief for liberal democracy; go read them instead.