Mark Twain said, "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so."
Of course we "all know" that income equality in the United States has been getting worse. Except that's not quite true. The chart below shows the Gini Coefficient for individuals, households and families since 1994. The Gini Coefficient is a measure of inequality where a value of 0 indicates perfect equality (everyone has the same 
income) and a value of 1 indicates perfect inequality (one person has 
all the income, while everyone else has none).  
As you can see, that measure for 
individuals (the people who actually get a paycheck) has not changed.  But that seldom gets 
reported because it contradicts the narrative of The Rich getting richer. What's reported is the coefficient for 
households.
If income equality for individuals hasn't changed, how can inequality for households go up? Simple. People with very high income earning potential are increasingly likely to form and maintain families. At the opposite end of 
the scale people with low earning potential are increasingly likely to be in single earner households.
So rising inequality has nothing to do with economics and everything to do with how people choose to form families or households. If you want to reduce inequality get married to someone with high earning potential and don't split up.