Actor/political liaison Kal Penn, who previously left his White House position to film A Very Harold and Kumar Christmas, will be making another trip back from the Beltway to Hollywood. TVLine reports that Penn will appear in a recurring role on the Emmy award-winning TV comedy How I Met Your Mother, set to premiere its seventh season on September 19.

The move would have Penn play Kevin, a possible love interest for Cobie Smulder’s character Robin Scherbatsky. Working on HIMYM would reunite Penn with a co-star from the Harold and Kumar movie franchise, Neil Patrick Harris (Starship Troopers, Doogie Howser, M.D.). NPH plays breakout character and hypocritical womanizer Barney Stinson, credited for much of the show’s success. The Washington Post’s entertainment blog Reliable Source comments on Penn’s unusual career path.> His unusual career path points to a little-known truth about showbiz: That even big-name actors have a lot of downtime between projects. It’s part of the reason you see many stars throwing themselves into campaign or celebvocacy work, with D.C. lobbying jaunts for favorite causes — though we’re hard-pressed to think of any others who took major pay cuts for public-sector gigs. (link)

Will Kal Penn ride the unicorn back to DC to continue pursuing his political passions after this latest acting gig? Or will this sitcom gig lead to more of KP on TV? It may be too early to say because, in the words of a certain vocal trio, “Don’t you know things can change“?

Update: ABC Nightline’s Jake Tapper interviewed Penn on the last day of his work at the White House. Penn reflected on the changing attitudes of young voters and what motivated him to get politically involved in a way that Hollywood actors (with the exception of perhaps Reagan or Schwarzenneger) rarely do.

“I had friends who were over in Iraq and Afghanistan,” Penn said. “I had buddies who had huge student debt, people who got kicked off their health insurance plans for one reason or another, and so that was my decision to get involved on a personal level.”

Seeing this job as an opportunity to serve his country, Penn said the experience has been “awe-inspiring.”(ABC)

He also shared a couple of memorable highlights from his time as a junior staffer at the White House, one involving an encounter with Chris Rock and the other a freezing midnight moment (captured at the end of an early 2011 edition of “West Wing Week”) helping to receive a rather large painting that Obama would give to the China’s president.