The smartest conservatives, ahead of the curve, are reframing the issue again. Maybe it doesn't matter whether sons are able to move up the hierarchy from where their fathers were, maybe what matters is whether kids generally grow up to have higher absolute incomes than their parents.I can see where Yglesias is coming from, in arguing that those attempting to reframe the issue fall among "the smartest conservatives". Yglesias, himself, has sympathy for the position and the article that inspired Yglesias's comment identifies the smart conservative, Reihan Salam, as one of the proponents of this redefinition.
But no, it's not going to happen.
Why not? First, because the "Horatio Alger" myth is central to Republican policy - tax policy, social policy, educational policy.... Consider how, four years ago, "Joe the Plumber" became the poster child for keeping taxes low on the rich. An average, blue collar guy who had aspirations of joining the 1%. You don't get the masses to rally behind regressive policies if you're blunt with them,
"You'll never benefit from these budget cuts and tax preferences, and your boss probably won't either, but rich people will keep a lot more money in their pockets. And your children will fare marginally better than you did, unless present economic trends continue in which case all bets are off."Second, once you start offering up the nation of "relative social mobility" you lend credence to the concept of "relative poverty", and for that matter to indexing the minimum wage to inflation, to "living wage" laws, and other measures to ensure that your promise of that modest economic improvement become a reality. By the same token, people want "more than that" for their children. People want to believe that their kids could grow up to be successful, even to become President. If while running for office you puncture those dreams with a, "Yeah, your kid might win the lottery, but odds are his life will only be marginally better than yours," even if it's true you're not going to see the working masses embrace your campaign.
Third, you open the door to people challenging you by pointing to past eras of greater income mobility, or other countries that enjoy greater income mobility, and asking "What's the biggest difference between then and now". If your answer boils down to, "The biggest difference is income inequality, and our tax policies and subsidies - which we are not going to change - have so significantly skewed that balance in favor of the rich that as long as you keep voting for us things won't get better and will probably get worse," once again people aren't going to embrace your policies or campaign.
Should our politicians be more honest both about the limits of income mobility and how present policy creates and perpetuates a de facto class structure? Probably so. But it's unlikely enough that Democrats are going to be that honest about a structure they helped create. It's simply not plausible that the modern Republican party is going to be that honest about the results of its key policies.