The arrest of ­Roman ­Polanski has revived ­memories of a really gross crime and the flogging of a favorite mid-American ­target: Hollywood liberals.

You know who they are. They’re the ones who are dragging America into the toilet with their filthy entertainment and socialist politics.

Just tuning in to a few ­minutes of talk radio this week brought an offhand comment about all the ­“Hollywood libs sticking up for Roman Polanski.”

Roman Polanski. Photo by Roberto Pfeil | AP.

The comment stems from petitions signed by some noteworthy filmmakers, including Martin ­Scorsese, demanding that the ­government of Switzerland release Polanski.

Polanski was arrested there last month and is fighting extradition to the United States, where he faces sentencing for having sex with a 13-year-old girl in 1977. Polanski was 43 at the time. He pleaded guilty but fled before sentencing in and has lived in France since then.

By any measure, what Polanski did was reprehensible. His victim, whom he plied with drugs and alcohol, was a girl — a seventh- or eighth-grader at best. Why anyone sticks up for him is hard for most of us to grasp.

But using the case and petitions to beat up ­Hollywood as a bunch of degenerates doesn’t square with reality, and neither does the idea that Hollywood is dragging the country into the gutter.

The thing is, facing ­reality makes the country face some uncomfortable truths about itself.

In an Oct. 6 post on his Big Picture blog, Los ­Angeles Times columnist Patrick Goldstein and screenwriter Josh Olson did a pretty thorough job of debunking the notion that petitions of support for Polanski were loaded with Hollywood types.

“Between the two ­petitions, there are ­approximately 650 signatures,” wrote Olson, whose screenplays include A History of Violence. “Of those 650, I noted ­everyone who could conceivably be ­considered a member of the Hollywood ­community. My rule was, basically, if you’ve done substantive and ­recognizable work for a ­Hollywood studio in the last four decades, you get counted.”

He counted 36 from ­Hollywood.

On that list were ­numerous foreign ­filmmakers, ­including Pedro Almodóvar, and writers ­including Salman ­Rushdie. ­Absent were Jerry ­Bruckheimer and Steven ­Spielberg, who almost anyone would acknowledge are real Hollywood power brokers.

Also, neither petition emerged from Hollywood. One was from New York-based producer Harvey Weinstein, and the other was from the Société des Auteurs et Compositeurs ­Dramatiques, which you might notice isn’t American.

But a lot of people easily accepted the idea that a “Free Polanski!” cry was ­emanating from the Left Coast, because it’s home to all these lefty perverts ­completely out of touch with the rest of the country. You can tell by all the sex and violence they try to shove down our throats in the movies and TV shows they foist upon the nation.

Again, that ­assumption falls apart on closer ­examination.

Yes, film and ­television continue to push the ­envelope in terms of ­content. But there’s a reason they do that, and this is the ­uncomfortable truth many people don’t want to face: America buys it.

As much as people like to paint filmmakers as a bunch of socialists, ­Hollywood ­really might be the most capitalist community in America next to Wall Street.

Look at what happened in Kentucky recently. The General Assembly passed a tax incentive for ­filmmakers. Once the incentive was passed, the Hollywood ­production Secretariat came to the state — because, like any business, it can make more money with tax rebates.

Yes, filmmaking is a creative endeavor, and in the best-case scenarios, ­commerce and art meet. But the bottom line is the ­bottom line out there. If a raunchy comedy full of ­nudity and crude jokes makes hundreds of millions of dollars at the box ­office, you know what you’re going to get: more raunchy comedies.

The same thing goes for crime flicks and torture porn. Saw VI, anyone?. The Saw series continues because the opening-weekend ­receipts are usually triple the production budgets.

People can protest all they want, but the way to get film studios’ attention is through the box office.
It should be noted too that although risqué, violent fare makes a lot of money, so does family stuff like the Pixar films and the Shrek movies, which is why those keep getting made, too.

It is perfectly fine to ­complain about movie, TV shows and Hollywood in general. Free speech. It’s American.
Everyone should just make sure they have the facts straight. And if people want to complain about what Hollywood is selling, look at what America is buying.