JEFF GREENFIELD:

What Plaster is talking about is called "gerrymandering"—the art of drawing districts to put as many of your voters together—or, more often, to make sure the other party's voters are broken up and scattered.

It gets its name from a nineteenth century politician named Elbridge Gerry. As governor of Massachusetts, he helped shape a congressional district so blatantly one-sided that one critic said it looked like a salamander. "No, another replied, a Gerry-mander."

Today, state legislatures across the country, the majority of them Republican, draw congressional district lines, something required with every new census every ten years to maximize their party's advantage.

That had particular impact after Republicans dominated the 2010 midterm elections, taking control of both legislative chambers in 25 states, and governorships in 29 states.