In a recent direct-mail piece, former Florida Gov. Jeb Bush made a startling admission:

"Americans could always count on hard work leading to higher incomes and improved lives. The American dream was real and within reach. But today, among the developed nations, we are the least economically and socially mobile country in the world."

In a fact check, Politifact confirmed the accuracy of Bush's statement:

"We're not going to sugarcoat it for you, folks, because there's plenty of evidence Bush's assertion is on the money (so to speak) .... Essentially, if you were born to a richer family, you had a good chance of staying there. If you were born into a poorer family, good luck. That trend is much more defined in America than it is in other countries."

As Politifact researchers document, economic mobility is much lower in the United States than in other developed countries such as Norway, Denmark, France, Germany, Canada and the United Kingdom. For example, people were almost twice as likely to move from the lowest quintile of income into the top income bracket in Finland, Denmark and Sweden as in the United States.

However, PolitiFact did not venture into the latter half of Bush's letter, in which the potential 2016 presidential candidate laid out his explanation for the fact that the United States is no longer the Land of Opportunity.

"How did we get here?" Bush asked himself. "To me, the answer is obvious: Our government has grown into a gigantic bureaucracy that is choking off economic growth." He then went on to argue that taxes and debt are too high, entitlements are out of control, regulations are out of control and our education system is failing.

The problem is, almost none of that is true.

Take government spending. In fiscal 2015, the federal government is expected to spend 21.4 percent of our national GDP. That is less than the 21.75 percent average during the eight-year presidency of Ronald Reagan some 30 years ago. Spending under Reagan fell below the 2015 number in only two of his eight years in the White House. The federal government, in short, is spending no more of our economic output than it was during the supposed Golden Age of conservative government. Bush is peddling myth.

Bush's explanation also fails on basic grounds of logic. Consider the fatal contradiction between these two points:

1.) Bush and his fellow Republicans blame the lack of economic mobility on high taxes, entitlement spending, regulation, etc.

2.) The countries that enjoy considerably greater economic mobility than the United States -- Denmark, France, Germany, etc. -- also have higher taxes, spend more on entitlements and regulate their economy more strictly than we do.

It's progress of sorts that politicians across the spectrum are at least acknowledging the reality of the problem. But a false and simplistic diagnosis of the cause gets us nowhere.