Thompson's latest casting call

Fred Thompson's acting career began by happenstance.

A political corruption scandal in Tennessee sparked a book by Peter Maas (best known as the author of "Serpico"), which in turn evolved into a movie. Thompson had represented the aggrieved state official at the center of the case and, when it came time to cast the film, the director tapped him for the role he had already played in real life. That launched a career that Thompson took seriously enough to cobble together a resume that untold numbers of actors in Los Angeles and New York must envy.

Happenstance also fueled Thompson's late-starting presidential campaign.  An unexpected chain of political circumstances left Republicans without a major contender from the South --- the party's stronghold. And the two front-runners who emerged early this year, Rudy Giuliani and Mitt Romney, had governed in liberal bastions --- and thus compiled records bound to chafe the GOP's rank and file.

Thompson answered the call from a cadre of supporters to enter the fray. He did it, however, in a fashion that has caused many to question his commitment. Those doubts now have been officially certified by a "Saturday Night Live" satire.

Let's give Thompson his due, though. Today, he's auditioning for a new part --- debate participant. And recognizing what's riding on his first appearance on the same national stage with his rivals, he's clearly taking it seriously: He left the campaign trail for a few days to prepare.

The New York Times recently noted that former Sen. Alfonse D'Amato of New York --- who had a rocky relationship with Giuliani --- has been assuming the role of the former New York mayor in mock debates. Thompson, along with prepping, also has been trying to manage expectations, saying he expects to be "a little rusty."

Attention will be squarely focused on Thompson, of course, but it's unlikely all that many will actually see his entire performance. The debate, taking place in Michigan and concentrating on economic issues, airs initially at 1 p.m. (PDT) on CNBC and then will be rebroadcast on MSNBC at 6 p.m. (It also will be live streamed on msnbc.com.)

Thus, Thompson's ability to compress his thoughts into a few worthy --- and articulate --- sound bites will be crucial. He doesn't have to "win" this debate; the format for these forums makes it difficult for any one candidate to stand out. Also, it's unlikely that the other candidates will go out of their way to direct much fire at him or try to put him on the spot. To do so potentially would elevate his status.

As a character actor, Thompson didn't need to dominate a scene; he just had to realistically inhabit his part and hold his own. That's his challenge today --- to show he belongs.

-- Don Frederick