Greg Sargent had a nice item today making a key point about the ongoing budget and sequestration impasse: that there’s no chance at all that it will end with Republicans getting an all-cuts, entitlement-slashing sequestration replacement. Why not? Because as bad as the sequester is for Democrats, replacing those spending cuts with cuts to Social Security and Medicare would be worse. So why should they make that trade?

Sargent concludes, as does Noam Scheiber, that therefore the chances for a grand bargain in which Republicans get entitlement cuts and Democrats get new revenue from closing tax “loopholes” are actually better than many believe.

I don’t see it. Begin where Sargent ends: “If Republicans really want to tackle the deficit, they just have to accept Yes for an answer.” Well, yes, but if the premise is wrong, so is the conclusion. I see no evidence at all that Republicans value deficit reduction over keeping taxes as low as possible.

Moreover, once everyone gets to the level of specifics, none of the spending cuts are popular, and it’s even difficult to find tax increases that are popular (some of those “loopholes” may be unpopular in the abstract, but once some middle-class folks who benefit from them can be found and we’re all told that job creation depends on these particular tax treatments…).

So I agree with Sargent that Republicans can’t get all they want, but my guess is still that the logical compromise will be very different from what he suggests. Instead, I think the way to keep everyone happy is if Republicans get their way on taxes and a nice-sounding deficit reduction number, but Social Security is left alone and the only Medicare cuts going through are provider cuts that most Democrats support. The rest? The obvious compromise is phony cuts, designed to get that top-line number but not actually cut popular programs in any significant way.

Granted, this course of action would be a public-policy disaster from the point of view of anyone who really believes that current and medium-term deficits are a major problem. But for actual Democrats and actual Republicans, it’s probably better than a grand bargain both in terms of public policy and politics.

At least, that’s the case if (as I suspect) very few people actually think that budget deficits right now are a bigger problem than other priorities.