Conservatives may overstate the impact, but few today would challenge the claim that the movie industry, or “Hollywood” in archaic shorthand, is staunchly, at times proudly, liberal in politics (Jon Voight, Clint Eastwood and Gary Sinise notwithstanding). This has been true for so long that most Americans–even right-wingers obsessed with this–have no idea how and why it happened. 

Those who know a bit about the history of the industry know that it was, in fact, founded, and managed for many years, by very conservative men from the East, mainly middle-aged Jewish immigrants. Actors and actresses were long known for contract disputes and sex scandals, not social activism. So when, and why, did the shift to the left occur?

Simply put: Those staunchly Republican studio chiefs were so afraid of famed Socialist writer Upton Sinclair winning the 1934 race for governor—after he swept the Democratic primary leading an amazing grassroots movement known as EPIC (End Poverty in California)—that they took several outrageous actions that inspired liberal actors, writers and directors to finally organize and speak out. And, as we all know, they haven't stopped since.

Those strong-arm studio tactics, what I've termed "Hollywood's first all-out plunge into politics," ranged from deducting one day's pay from all of their employees (including top writers and actors) for the Republican candidate's slush fund to the creation at MGM—by saintly producer Irving Thalberg—of faked newsreels, the precursor of "attack ads" on TV that dominate campaigns today (see below).

Just one longterm effect: The Screen Writers Guild and Screen Actors Guild had each been formed in 1933 but were attracting little big name talent until the backlash to the 1934 campaign arrived. Soon they were for the first time successfully challenging the bosses on everything from contracts and working conditions to bullying political tactics. And they led the fight that elected a Sinclair ally governor in 1938. More and more films with a progressive point of view appeared. 

I first revealed much of this story in my award-winning 1992 book for Random House, The Campaign of the Century: Upton Sinclair’s Race for Governor of California and the Birth of Media Politics. The Hollywood angle was just one of the wild and wooly highlights of the book. You can read a full summary in my Nation feature from a few years back.

For some readers, The Campaign of the Century, however entertaining and eye-opening, suffered from one drawback:  It takes over 600 pages to tell its tale. And it does so in a day-by-day chronology, meaning, for example that the Hollywood segments are scattered throughout. Some have suggested, for two decades now, that I break out the movie material into a separate, easier-to-consume narrative. 

Now, with the added advantage of electronic publishing, I’ve finally done that, in an e-book published this week, When Hollywood Turned Left, adding a new Introduction, revising throughout and offering a new Appendix with fresh copy (such as an interview with Billy Wilder). So it’s something borrowed, something new.  And there’s plenty of star power: Jimmy Cagney and Louis B. Mayer, Charlie Chaplin and Katharine Hepburn, Will Rogers and William Randolph Hearst,  Dorothy Parker and H.L. Mencken, and on and on.

Until now I'v never explained how I became the first to find these long-rumored forerunners of today’s ubiquitous election commercials on TV. All I knew were claims that MGM somehow had a hand in producing them. No one, since 1934, had ever claimed to view them. Perhaps they were lost to the ages. I cast my net wide but concentrated on MGM history and archives—and one day got a call from a staffer who helped manage the studio’s collection of old film shorts in Los Angeles (not at the old Culver City complex). He had found listings for three shorts from 1934 labeled “California Election News.”

So I flew out there as soon as possible and screened the footage and, sure enough, the mystery was solved. Researchers and Hollywood mystery buffs had probably concentrated on searching for “newsreels” instead of film shorts. 

Hollywood’s obsession with the campaign crossed all lines, however. “The Sinclair campaign marked a turning point in Hollywood’s participation in almost all respects,” Ron Brownstein would judge in his book The Power and the Glitter.  The “desire for unfiltered political expression—and the hunger to declared independence from the studio fathers—inspired a grassroots leftist surge that transformed politics in Hollywood.”  

One conservative movie producer would sadly admit, referring to the liberal backlash that would change the movie industry forever, “I guess we started something in 1934.” 

Greg Mitchell has written more than a dozen books, with When Hollywood Turned Left just the latest.  He's been chief advisor on several documentaries and is co-producer of the new film, "Following the Ninth."