And he [Louis Brandeis] talks to his young acolyte, Horace Kallen, who wrote this beautiful book called Cultural Pluralism, and he comes to believe that by being better Jews, or better members of our ethnic group, we can be better Americans, because America is like an orchestra in which identity is defined by the diversity of perspectives that we bring to the table.

I'd say that [Louis] Brandeis practiced a kind of a "living originalism," to use the title of Jack Balkin's great book. He said you start with the paradigm case, which in the case of the Fourth Amendment was these general warrants or writs of assistance, but you define it at a level of abstraction that you can take it into our age and make it our own.

Do you think Bernie Sanders, for example, is citing Theodore Roosevelt as the progenitor of his critique of the banks when actually Roosevelt wanted to keep the banks together and regulate them.

We need to protect the same amount of cognitive liberty in an age where you can invade people's thoughts without physically intruding into their homes than you did at the time of the framing.

We shouldn't let the Republicans off the hook. Theodore Roosevelt, we learned from Jeff Cowan's new book, was just as bad as certainly [Louis] Brandeis was, or many Democrats were on the question of segregation.

Louis Brandeis really inspired me to write this book [Louis D. Brandeis: American Prophet]. It was a crazy deadline. The editor said I'd miss the hundredth anniversary unless I pumped the thing out in six months, because I'd been delaying and dilly dallying for so long. So he both inspired me to get up early and write.

Unlike [Woodrow] Wilson, Louis Brandeis did not support the segregation of the federal government. He was personally courteous to African Americans. He advised them and advised the head of Howard University to create a good law school. And that inspired Charles Hamilton Houston and Thurgood Marshall in their path-breaking work on behalf of desegregation.