Kal Penn is spotted on the floor of the Times Warner Arena where the Democratic National Convention in Charlotte, N.C. on September 3. (Photo by Marlon Correa/The Washington Post) (Marlon Correa/THE WASHINGTON POST)

In the hit stoner film “Harold and Kumar Go to White Castle,” two college buddies are on a quest to satisfy a serious case of the munchies with White Castle burgers. It’s not the usual first job for a political player, but actor Kal Penn, who plays Kumar Patel in the film, somehow parlayed that experience into a very different role — first at the White House and now at the Democratic Convention.

Penn will address delegates and guests Tuesday at 9:20 p.m. EDT in Charlotte before First Lady Michelle Obama takes the stage. He also has another gig Thursday at 8 p.m. hosting the live online coverage of the convention at BarackObama.com. So how did the actor’s journey to White Castle lead him to the White House, as associate director in the Office of Public Engagement, and now, to a speaker’s spot at the convention?

For starters, he goes by his real name in his political profession, KalpenModi – and his juggling of conflicting interests in politics and acting dates back to his youth. He went to University of California-Los Angeles in the mid-90s, where he majored in sociology and film, and landed supporting acting roles until his leading break as a fictional pothead.

But it was Barack Obama who resurfaced Modi’s political interests when Modi met the presidential hopeful in 2007. The actor, who was playing Dr. Lawrence Kutner on the television show “House M.D.,” campaigned aggressively for Obama during the 2007-2008 writers’ strike and served on the campaign’s arts policy committee.

After the election, it was clear Modi had caught the political bug. His character on “House” committed suicide, so he could trade scrubs for suits and take a position as associate director in the White House Office of Public Engagement. He played the role of liaison to young Americans, the arts, and Asian American and Pacific Islander communities.

Because of a prior commitment, Modi was pulled away from his staffer duties in April 2009 and back onto the big screen for a third “Harold and Kumar” feature, “A Very Harold and Kumar 3D Christmas” (they had also “escaped from Guantanamo Bay” in 2008). But he returned to the Old Executive Office Building in November 2010.

His affair with acting continued in 2011 with appearances on the hit show “How I Met Your Mother “and “House,” in an episode called “Everybody Dies.” Yet this year, he’s answering the president’s call to serve on his campaign — quite literally.

In a Web ad promoting BarackObama.com’s live online coverage Thursday, President Obama makes a mock-serious call to Modi, who plays his pothead character alongside “Harold and Kumar’s” John Cho.

“I’m counting on you. Everybody is. We have to get this right,” Obama said.

Until his hosting duties, you can catch Modi Tuesday night onstage at the convention.