With hours to go until his boss faces voters for the first time in eight years, Robby Mook was doing the same, knocking on doors in a small corner of a Des Moines suburb.

Hillary Clinton’s campaign manager could’ve spent Saturday afternoon holed up in headquarters, shuttling around the state with the candidate, or schmoozing politicos in the lobby of the Marriott. Instead, he was making his way through a solidly middle class Urbandale neighborhood, checking in with committed supporters.

“Hey! My name’s Robby. I’m here with Hillary Clinton’s campaign,” he says once it's clear that the person answering the door is the person on the list of confirmed supporters that he picked up from a nearby field office, just as any volunteer would. “I was just coming by to remind you about the caucus on Monday.”

Though two Bloomberg Politics journalists spent about 45 minutes watching Mook visit 15 houses on a gray but warm-for-January afternoon, it wasn’t just a photo-op. He would’ve been doing this without reporters watching him and planned to do it again on Sunday and Monday, schedule permitting. In all, people at eight houses answered their doors, five of whom said they would be caucusing for Clinton. At one door, a man supporting former Florida Governor Jeb Bush said that his wife—who was out of the house when Mook visited—was the Clinton supporter. At another, a man identified as a Clinton supporter seemed to be engaged in a tense moment with his son. A woman said she and her husband were Clinton supporters but that she had a doctor's appointment and may not be able to make it.