Chris Hayes and Kevin Drum have been commenting on the odd phenomenon of Republican politicians constantly invoking the hardship of their parents and grandparents. Almost without fail, GOP politicians reach back as far as they need to in their family history to find some story about someone coming from humble beginnings and doing better for themselves. On its face, this seems very strange: who cares what someone’s grandparents did? On second glance however, it’s not strange at all: these stories are meant to spread the myth of US social mobility.

Last year when Occupy Wall Street pushed inequality into the spotlight, Republicans shot back with the exact same stories of their distant ancestors achieving social mobility. I wrote about it at the time. Eric Cantor’s cancelled speech on inequality is probably the best demonstration of what the GOP has in mind when it shares these stories. Mixed in with his grandmother’s story of economic success, Cantor gives the standard line about equal opportunity and social mobility:

It really is about that fair shot – no matter who you are or where you’re from, all of us should have access to the opportunity to earn your own success. The basis upon which America was founded and the basis upon which America thrives is providing people with the equality of opportunity – not equality of outcome.

There is a ladder of success in America. However, it is a ladder built not by Washington, but by hard work, responsibility and the initiative of the people of our country.

Of course, the problem with these stories is that they do not reflect the overall reality. To be sure, some poor people do manage to rise up, but we have pretty solid data on how frequently that happens. As it turns out, it does not happen very often.

People born in the richest 20% are 10x more likely to wind up there as adults than people born in the poorest 20%. The empirical evidence shows that the US has low social mobility, and certainly does not have equal opportunity for all. This is a problem for right-wingers because social mobility and equal opportunity are the institutions they rely upon to justify current levels of inequality. Those levels of inequality are said to be permissible because they reflect merit and hard work, and anyone can move to the top if they try hard enough.

When GOP politicians tell stories of upward mobility among their ancestors, their goal is to plant the impression that equal opportunity and social mobility are real and alive. They are not responding to voter desires to hear about some candidate’s humble beginnings and they are not stupid. These narratives form the core of right-wing understandings of economic fairness, and even though the stories are statistical outliers, Republicans rely upon them to insist that the US is an economically fair society.