Napolitano says she first met President Obama when she was chair of the National Governor's Association. A picture of the two hangs prominently in her office.
"Ladies and gentlemen, the president of the United States accompanied by Secretary Janet Napolitano," an announcer's voice booms.
Napolitano raises her right hand, and swears in new U.S. citizens, offering her congratulations.
"It's really one of the most if not the most enjoyable parts of my business which is the nationalization of new citizens," she tells ABC News afterwards. "These young men and women are already in the military, they're already serving their country so, we have naturalized since 2001 over 58,000 military members. It's one of our big programs and we're actually looking to expand it."
On the way to more briefings, there is a chance to chat about the secretary's future. She's on a shortlist for an upcoming Supreme Court vacancy -- a subject she defers addressing.
"I'm flattered to have it asked. We'll just leave it at that," she says, when asked whether she would accept a nomination from the president.
The day starts to become a blur. Next stop -- a meeting with the president of Air Canada to discuss commerce and airline security. Then it's time to record a public service announcement.
"Right now we're helping prepare a video that will be used for law enforcement to help detect the signs of trafficking which is often a crime in plain sight but you don't see it unless you know the signs. We do these on a routine and it's part of our responsibility," she says.
Outreach is part of the job -- and Napolitano has tried some surprising venues, such as Comedy Central's "The Daily Show" and "The Colbert Report", and ABC's "The View".
"The point is to reach different audiences," Napolitano explains. "We can't do everything inside Washington, D.C. nor should we."
"The shows are kind of fun to go on anyways. But the goal is to expand the outreach of homeland security," she says.
Then it's back to the White House for another emergency meeting on the oil rig disaster.
Next up? The year's first briefing on hurricane preparedness.
Then on to a Transportation Security Administration rally. TSA employees say they have been under incredible pressure since the Christmas Day attempted bombing.
For her, preventing terror is the number one mission. Napolitano sums up the job in her typical blunt style.
"Our job is to do everything we can to minimize the fact that one of these threats will actually materialize into harm to the United States," Napolitano says. "It's regrettable and in some ways unfathomable, but it's real and we've got to deal with the reality of it."
She warns al Qaeda is trying desperately to score a direct hit.
"They remain an ever-present threat," she says. "One of the things we've seen over the last year is the phenomenon of U.S. citizens traveling to the [federally administered tribal areas], traveling to Yemen, to learn the tactics used by al Qaeda and then coming back," Napolitano says.
The reality of the threat was underscored last Christmas Day, when a 23-year-old al-Qaeda-trained Nigerian named Umar Farouk Abdulmutallab boarded Northwest Airlines Flight 253, and attempted to ignite a bomb sewn into his underpants. He was thwarted by fellow passengers.
After the incident, Napolitano was criticized for initially saying "the system worked."