If cronyism had truly been the dominant force in our economy for decades, we would have stagnated long ago. The economic booms of the 1980s and 1990s would not have happened. Ordinary Americans today would have no smartphones, no GPS navigation, no digital photography, no e-books, no Amazon.com, no big-box retailers, no access to miracle drugs such as statins and PDE5 inhibitors? This list can be extended much further.
Yet even if I here underestimate the extent of cronyism, the problem with cronyism isn't that it makes incomes less equal. The problem is that it stifles economic growth and, worse, violates the property and contract rights of ordinary people in order that government can transfer unearned treasure to politically powerful special interests. Any resulting rise in income inequality is merely a symptom of cronyism's evils. Efforts aimed directly at making incomes more equal, therefore, miss the mark. Such efforts not only penalize non-cronies, but by attacking merely a symptom of cronyism, these efforts divert attention from and leave intact the destructive cronyist policies themselves.
Were I a crony, that's a situation that I'd find to be most convenient.