Just how exceptional is America really? Everyone loves to talk about American exceptionalism. We constantly hear our politicians say that “America is the greatest country in the world.” But just how great are we?

In reality, when it comes to things that could really make America great, we’re lagging behind much of the developed world.

Take healthcare for example. A study earlier this year by the Commonwealth Fund found that of the top 11 developed nations, the United States ranks dead last in health care and health outcomes like infant mortality and life expectancy. A similar report from the World Health Organization ranks our healthcare system 30th in the world - although we pay more per person for our health care than any other developed country in the world.

Meanwhile, while America is at the bottom of the healthcare barrel, we’re also far behind when it comes to education and educational outcomes. Last year, the Program for International Student Assessment looked at how 15-year-old students in 65 nations across the globe performed on a variety of tests. The group found that U.S. students ranked just 17th in reading comprehension and 21st in math. And similar studies have found that among developed nations, the U.S also comes in towards the bottom in educational attainment, or the highest degree of education an individual has completed.

But as America is lagging behind in education and healthcare, we are leading the world in one thing: violence. According to a study by two New York City doctors, the United States has a staggering 88 guns for every 100 people, and has 10 gun-violence related deaths per every 100,000 people. Both of those stats are higher than any of the other 27 developed countries that the doctors looked at.

So, what’s the common denominator here? What links poor educational outcomes, poor healthcare outcomes and high levels of violence all together? It’s the inequality stupid!

Thanks to America’s 34-year-long failed experiment with Reaganomics, right now we are seeing unprecedented levels of wealth inequality. Today, the 400 wealthiest Americans own more wealth than the bottom 150 million Americans combined. Similarly, the wealthiest 1% of Americans now own more than 35% of America’s wealth, while the bottom 50% of Americans own just 2.5% of this nation’s wealth. And, over the past 15 years - the annual income of the typical American household has fallen by 9%

The wealth gap in the U.S. today is as wide as it was in 1928, just before the Great Depression. As Yale University economist Robert Schiller put it, “The most important problem that we are facing today...is rising inequality...” Inequality alone is a huge problem, but as Richard Wilkinson and Kate Pickett point out in their book “The Spirit Level,” higher levels of inequality directly cause a host of other problems.

For example, they found that health and social problems are worse in more unequal countries, like the U.S., which comes in dead last in their study. Those health and social problems include things like life expectancy, infant mortality, homicides, child wellbeing, math and literacy rates, mental illness and imprisonment.

So, while jingoistic politicians might argue that America is the greatest country in the world, the facts really speak for themselves: We aren’t and inequality is to blame. Fortunately, we can change that. We can become exceptional once again, and become the “city upon the hill” for the rest of the world to emulate.

That starts by fighting income inequality by rolling back the Reagan tax cuts, giving labor better protections, and making corporations pay their fair share to support the American economy. America will only be exceptional when all Americans have an equal shot at success.