Because of the centrality of race to the Democratic nomination contest, Hillary Clinton’s advocacy of tough-on-crime measures in the 1990s — and Bernie Sanders’s votes for those measures — have come up regularly on the campaign trail.

It came up during Sunday night’s debate, too, and Sanders made a promise meant to show his commitment to reversing the system of incarceration that resulted.

“Where we are right now,” he said, “is having more than 2.2 million people in jail — more than any other country on Earth. This is a campaign promise: At the end of my first term, we will not have more people in jail than any other country.”

That’s a big commitment, for two reasons.

The 2.2 million figure comes from the Bureau of Justice Statistics, which we can compare to the populations in other countries, thanks to data from the Institute for Criminal Policy Research. The United States’ prisoner population is about 34 percent higher than that of the next highest country, China.



China, as we noted in December, has a relatively low population of prisoners relative to its size (in part because of its aggressive system of capital punishment).

To reduce the population of the incarcerated beneath China's level, we'd need to release more than one quarter of those who were in prison at the end of 2014.

That’s hard in and of itself. But it’s even harder as a campaign pledge from Sanders because most of the country’s prison population is incarcerated at the state level.


The graph above shows the prison population. At the end of 2014, there were another 745,000 people in local jails. As president, Sanders would have little ability to affect how states and municipalities or counties deal with their own prison populations. He’d need congressional legislation — and approval from a Republican House and a Senate with at least enough Republicans to filibuster — for a bill that would set one-fourth of America's prison population free on the streets.

Which seems unlikely.