Bernie Sanders regularly calls for a "political revolution" in America, but what does that mean? (Peter Stevenson/The Washington Post)

Bernie Sanders wants a revolution. But what, exactly, does that mean?

Sanders’ definition of “revolution” can be broken down into two parts: revolution against centers of power in America -- especially big banks and Wall Street investment firms -- and also the way we elect politicians as a whole.

The Vermont senator wants to enact a series of social welfare policies that would give Americans benefits like expanded health insurance, free college tuition and guaranteed leave for new parents – all paid for by increased taxes on large corporations and wealthy individuals.

Worth noting here is that his “revolution” is heavy on domestic policy and decidedly light on foreign policy -- something for which Sanders has been criticized, especially after the first three Democratic debates, when he seemed to turn every question back to the economy and “the billionaire class.”

But it’s not just a revolution in policy that Sanders is looking for. It’s also a revolution in the way our elected officials are voted into office. Spurning super PACs and corporate contributors in favor of small contributions from individual donors has been one of the hallmarks of his campaign. In December, his campaign announced that it had received more than 2 million individual donations from more that 1 million individual donors.

And it’s not just the number of donors that Sanders is counting on; it’s who they are. His success hinges largely on young voters (specifically white, liberal ones) -- a group that historically makes a poor showing at the polls. But thus far, those young voters have flocked to his campaign events in droves. If he can leverage the enthusiasm that is evident at his rallies into strong showings in the primaries, his challenge to Hillary Clinton – still the presumptive Democratic front-runner to many – could endure for longer than she'd like.

If Bernie Sanders wants to see the revolution he keeps asking for, it will need to come in two forms: both in new laws, and a new political system in which his base actually turns out to vote to elect him president.