Obamacare is becoming a huge weapon in the fight against inequality.

This shows up clearly in this New York Times piece. It uses data from Civis Analytics to understand, on the most micro-level, how the Affordable Care Act is changing America.

For the richest enclaves, Obamacare hasn't been a giant deal. The uninsured rate for people who live in America's highest-income counties just slightly budged downwards, from 8.2 to 6.5 percent over the health law's rollout.

But for those who live in low-income areas, Obamacare has made a world of difference. The uninsured rate for residents of poor counties fell by 9 percentage points, from 26.4 percent in 2013 to 17.5 percent now.

Obamacare matters the most for low-income Americans, who have typically faced barriers to gaining coverage.These are the people who are less likely to have a job that offers health benefits. Or, if it does, many still find the premium too expensive. The individual market has been an inhospitable place for poor Americans, who could get locked out due to a pre-existing condition or not afford the higher prices. Insurance has, for decades, been something of a luxury good.

What we're seeing now is Obamacare as an equalizer, giving lower-income Americans access to the benefits that have been held out of reach. Part of this is also through the health care law's increased taxes on the wealthy, adding things like a Medicare tax on income above $200,000.

Obamacare would be reducing inequality even more if all states were participating in the Medicaid expansion and growing the public program to cover all residents below 133 percent of the poverty line (about $15,000 for an individual). Right now, only 27 states and the District of Columbia have signed on board.

But even without Medicaid expansion, the law has already become a force against inequality, getting coverage mostly to groups that have been shut out of the insurance market.