I know that some Republicans will claim that adding two states is just a ploy to help the Democratic Party. But if the people of Washington and Puerto Rico want to be represented by Democrats, they should have that right. Plus, they might sometimes choose Republicans, as the conservative pollster Patrick Ruffini has suggested. Puerto Rico’s current (nonvoting) member of the House of Representatives is a Republican, Jenniffer González-Colón.

Adding two new states is a far more achievable idea than many of the other democratic reforms being bandied about these days, like Supreme Court term limits. Granting statehood has been a regular part of this country’s history. It happened in every decade from the Constitution’s ratification in the 1780s through the 1910s, when Arizona and New Mexico joined. Then it happened again in 1959, with Alaska and Hawaii. That most recent expansion was now 59 years ago, which means the country has never gone so long without adding a new state.

To do so, Congress would need to pass a bill, and the president would need to sign it. Clearly, the current Congress and president won’t do so, but they won’t be around forever. They may not be around by January 2021.

If you think about the four youngest states — Arizona, New Mexico, Alaska and Hawaii — you may notice a pattern. Like Puerto Rico and Washington, they are home to a lot of nonwhite people, which is not a coincidence. This country has historically been slow to grant full enfranchisement to people with darker skin. Try to imagine if the four million people who lacked Senate representation today were upper-middle-class white suburbanites. Or imagine the Fox News outrage if they were white evangelicals. They’d have a legitimate grievance, too.

To measure the gap between the political power that the Senate currently bestows on white and nonwhite citizens, I did a little math. I started by calculating the number of senators per million people for each state and territory — numbers that you can see in the chart above. I then looked at the ethnic breakdown of each state and territory to create a nationwide senators-per-million-people average for each major ethnic group. The average for black Americans, for example, takes into account how many live in California, Texas, Wyoming, Washington, D.C., and so on .