Victor Davis Hanson explains for National Review Online readers that the historical record offers a disheartening picture for societies that politicize their tax enforcement.

Why did Rome and Byzantium fall apart after centuries of success? What causes civilizations to collapse, from a dysfunctional fourth-century-B.C. Athens to contemporary bankrupt Greece?

The answer is usually not enemies at the gates, but the pathologies inside them.

What ruins societies is well known: too much consumption and not enough production, a debased currency, and endemic corruption.

Americans currently deal with all those symptoms. But two more fundamental causes for decline are even more frightening: an unwillingness to pay taxes and the end of the rule of law.

Al Sharpton is again prominently in the news, blaming various groups for the Baltimore unrest. But Sharpton currently owes the U.S. government more than $3 million in back taxes, according to reports. His excuses have ranged from insufficient funds to pay them to sloppy record-keeping and mysterious fires.

Sharpton, a frequent White House guest, apparently assumes that his community-organizing provides him political exemption from federal tax law. He seems to be right, at least as long as the current administration is in power. …

… In the current political landscape, ideology also offers cover for tax noncompliance. Two of the most liberal talking heads at the MSNBC cable news network, Touré Neblett and Melissa Harris-Perry, known for their advocacy of higher tax rates on the affluent, turn out to be both quite well off and quite unwilling to pay their fair share of taxes. Reports indicate that Neblett and Harris-Perry both owe more than $50,000 in delinquent taxes.

Who will police the tax police?