Elizabeth Bruenig writes:

The impact of inequality on the overall economy and political climate means that, unless inequality itself is reduced, individual initiative won’t have much impact and conditions for ordinary people in America will continue, in key ways, to worsen.

Sanders himself agrees. “You have an economic situation where a tiny number of people have enormous amounts of wealth,” Sanders told me at his Senate office Wednesday morning, “and politically, you have the Koch brothers and a handful of billionaires buying elections.” Sanders pointed out that the top 1 percent of earners would rake in roughly 83 percent of the benefits of President Trump’s tax cuts, a series of policies for which Koch-led groups spent more than $20 million. As Yale University political scientist Jacob Hacker pointed out in The Post, the decision to supply a generous tax cut to the rich — greatly encouraged by the vast wealth of billionaire donors — is a de facto decision to reduce expenditures that help ordinary Americans, “like public investments in infrastructure, education, research and development, and the regulation of labor and financial markets.” Put simply, inequality allows the wealthiest Americans to exert undue control over politics, thereby maintaining the conditions that made them rich in the first place, and hamstringing government efforts that could increase opportunities for the rest of us.

And inequality weakens the economy itself. Economic researchers have argued that American inequality worsened and prolonged the negative effects of the Great Recession and that continued inequality has left less well-off families more vulnerable to economic shocks going forward, meaning that future crises might unfold even more disastrously than the last.

Most important, rising inequality can swamp the gains that broadening opportunity is supposed to deliver….

If Democrats want to formulate a bold, enduring political vision that will speak to the future that Americans want for themselves, they need to accept that opportunity is a result and companion of equality, not a separate choice altogether.