Last Sunday Jorge Castañeda wrote an opinion piece in the New York Times Sunday Review warning Americans what happens when a country doesn’t have a middle class. Yesterday he extended his argument in an hour-long interview with Tom Ashbrook. Castañeda argues that economic inequality in general — and the lack of a strong middle class specifically — inhibits public security, political stability, and sustainable economic growth.

Latin America has long been the most unequal region in the world; whereas the modern notion of the “middle class” — an intermediary between the nobility and peasantry — is tied to the independence of the United States. But now, argues Castañeda, we are beginning to see initial hints of a role reversal. There is intense debate about what it means to be middle class in America today, but researchers unanimously agree that income segregation has been steadily rising since 1970. Meanwhile, in many Latin American countries like Brazil, Mexico, Uruguay and Chile, the middle class has been steadily growing over the past couple decades, leading to consistent economic growth and the consolidation of democracy in all four countries. (None of the four countries were true democracies in the 1980’s.)

Now the US government is set to run out of money (yes, again) in a couple days and the IMF’s Christine Lagarde is asking Latin American countries to bail out Europe.

How did Europe become so steeped in debt in the first place? The map below shows those European countries — the same ones at risk of defaulting today — with the highest income inequality:

It is important, however, to not give too much hype to “the new global middle class.” Castañeda is cautious to note that even the fastest growing Latin American countries are still much more unequal than the United States:

In Brazil, Chile and Mexico, which together account for nearly 70 percent of the region’s G.D.P. and population, the wealthiest 10 percent held an average of 42 percent of national income in 2008-9; the equivalent figure for the United States was 29 percent.

And, in fact, Castañeda himself wrote an entire book which argues that Mexico’s new middle class won’t bring about true democratization and modernization unless it is accompanied by substantial cultural changes. Classism in Mexico is startling. Two recent examples: a few months ago a video was uploaded to YouTube of two upperclass young women who were stopped at an alcohol checkpoint in one of Mexico City’s most luxurious neighborhoods. The hysterical, and clearly intoxicated, women screamed at the police officer calling him a “naco asalariado,” which is nearly impossible to translate, but along the lines of “redneck hourly wage earner.” (Yes, that is apparently considered an insult among Mexico’s wealthy.) Another recent example: after Mexico’s leading presidential candidate failed to name the title of a single book other than the bible, his daughter retweeted the following: “Greetings to the bag of proletarian shitheads that can only criticize what they envy.”

Mexico’s inequality may be diminishing, but its cultural classism is as strong as ever. Similarly, Greg Michener reminds Brazilians taking delight in their newfound role of lender to the IMF that there are still plenty of problems at home.

All of this is of great personal consequence to me. One of the most difficult challenges for me to adapt to Mexico has been its relative lack of a middle class. Sadly, I have a difficult time relating to both the wealthy and the poor, which leaves me with a fairly thin slice of the social pie, even if it is growing. It is also what I miss most about the United States; a well-educated middle class that actively participates in civic life. It pains me to see middle class disappearing in the United States, though it gives me hope to see it emerge in parts of Latin America. Could it be time for both regions to launch pro-middle class campaigns?

Kwame Anthony Appiah’s latest book charts the movement for moral rights — from the conception of natural rights within religion to secular human rights with the birth of democracy to legal civil rights in the last century. Earlier this year, in a fascinating interview with Appiah, Christopher Lydon pondered when the next great movement for the right to equality will finally gain steam. A couple months later and protesters brought their tents to Wall Street.

Despite its many failings, the Occupy Movement has put economic equality back on the agenda in the United States and much of Europe. In Mexico, however, the greatest advocate of economic equality, presidential candidate Lopez Obrador, has been branded a dangerous Chavez-like populist by the mainstream media. Unlike Brazil, where Lula and Dilma have confronted inequality without scaring away the private sector, Mexico has yet to find a political leader who can frankly discuss the issue without being labeled a populist. Brazil’s success has been rooted in pragmatism not politics, writes Anand Giridharadas, but here in Mexico it seems to be all politics all the time.