Inequality and social cohesion

Robert Reich in the New York Times:

I’m 67 and have lived through some angry times: Joseph R. McCarthy’s witch hunts of the 1950s, the struggle for civil rights and the Vietnam protests in the 1960s, Watergate and its aftermath in the 1970s. But I don’t recall the degree of generalized bile that seems to have gripped the nation in recent years.

The culprit for this alleged rise in bile? What else -- income inequality:

Widening inequality thereby ignites what the historian Richard Hofstadter called the “paranoid style in American politics.” It animated the Know-Nothing and Anti-Masonic movements before the Civil War, the populist agitators of the Progressive Era and the John Birch Society — whose founder accused President Dwight D. Eisenhower of being a “dedicated, conscious agent of the Communist conspiracy” — in the 1950s. 

Inequality is far wider now than it was then, and threatens social cohesion and trust.

Let's see if this stands up to even rudimentary scrutiny. Here's one typical measure of inequality:

If Reich's theory is correct, the rise in inequality starting around 1980 should correlate with a breakdown in social cohesion.  

In the 1960s the US witnessed the assassination of a variety of political figures: President Kennedy, his brother Sen. Robert Kennedy, Martin Luther King and Malcolm X (while the former two were not elected officials, they certainly were prominent political voices). In the early 1970s George Wallace was shot while campaigning for president. President Reagan was shot less than three months into his presidency in 1981.  

Since Reagan's shooting the US has experienced zero shootings of presidents,  presidential candidates or members of Congress. The US did experience a huge incident of domestic terrorism in the 1994 Oklahoma City bombing, but there is no evidence that this was driven by Timothy McVeigh's anger over insufficiently high tax rates on the rich or any other issue related to inequality.

Wikipedia's list of US riots and civil disturbances, meanwhile, counts 68 for the 1960s and 49 for the 1970s compared to 14 for the 1980s, 11 for the 1990s and 24 for the 2000s. Both violent and property crimes, arguably other indicators of social cohesion, have declined since 1980.  

Robert Reich and his ideological fellow travelers remain convinced that inequality is the root cause of all sorts of social and economic ills. Someday they might even come up with some supporting evidence.