There are loads of buttons available at the convention, but not many come in individually numbered, limited editions.

Perhaps the most coveted button of the 2008 convention in is a small green button with the number 300 interlaced with a picture of a pen. The button—whose theme comes from the hit movie 300, about the Spartans who defended Greece from the Persians at the battle of Thermopylae—is being worn by the 600 or so Hillary delegates who over recent weeks petitioned to force a full roll-call vote at today’s convention. When it looked as though the party might try to broker unity after the long, protracted primary battle between Hillary Clinton and Barack Obama by skipping the roll-call vote, they swung into action. Yesterday, when it seemed possible that the party would cut off the roll-call vote early, the 300 (who are actually more like 600) swung into action again.

These are the Hillary die-hards—the ones so passionate about their support that they created the unique button, numbered each one, and distributed them to the hundreds around the country who would wear them at the convention. The buttons are worn with immense pride—they identify to each other the powerful and not-so-small clan that is seeking today to represent the 18 million Americans who voted for Hillary. Watch today’s roll-call vote carefully and you’ll probably see the button on old pals or shirts of many of the Hillary delegates.

Garrett Graff is in Denver all this week, reporting from the Democratic National Convention. Head here for his coverage of parties, people, politics and more.