How big is the difference in voting rate among the rich and poor?

It’s stark at the very top. One study found that around 99 percent of the top 1 percent voted in 2008, compared with 49 percent of the people making less than $10,000. And according to 2010 census data and 2012 exit poll numbers ...

■ About 50 percent of households made less than $50,000 a year, but that group punched below its weight, representing only 41 percent of the turnout in the election in 2012.

■ About 20 percent made more than $100,000 a year, but that share of the 2012 turnout was 28 percent.

Low participation among the poor contributed to a dismal voting rate of less than 37 percent in the 2014 midterm elections.

Would our policies be different if there were compulsory voting?

Recent research has shown significant differences between voters and nonvoters.

Before the 2012 election, a Pew study found a strong preference for President Obama over Mr. Romney among nonvoters: 59 percent support for Mr. Obama versus 24 percent for Mr. Romney. The study also found that nonvoters expressed a greater appetite for progressive taxation and a bigger role for government. In other words, these are Mr. Sanders’s people, and the playing field would be expected to tilt to the left.