Several responses to a recent column about Minnesota's Sixth Congressional District and income inequality suggested that the obvious answer to why it leans Republican is that it's predominantly a white district.

It is certainly true that the Sixth district is predominantly white, at about 92 percent as of the most recent U.S. Census Bureau data.

But it is not the Minnesota district with the highest percentage of white residents. In fact, the First, Seventh and Eighth districts all have a higher percentage of white residents than the Sixth. Each of those districts is represented in Congress by a Democrat.

What's interesting is that of the four districts, the Sixth easily has the least amount of income inequality, as measured with something called the Gini index. Its Gini index is 0.385, and as noted in the column, it's the lowest of all the congressional districts in the land.

That's what made it noteworthy, a very low level of income inequality, not its percentage of residents who identified themselves as white.

It's also important to note that Minnesota as a whole does not have the same level of income inequality as the rest of the country. The other three districts in the state with a higher percentage of white residents than the Sixth all have a Gini index that is lower than the national average.