I am always buoyed when someone who is all too easy to dislike reveals a glimmer of unexpected grooviness or humanity. I’m happy to put myself down as a stereotyper — even a bigot — in return for being surprised that a person once thoroughly dismissed by narrow-minded me has affection-worthy dimensions.

I stopped in my tracks when Ali MacGraw told me that Richard Nixon was one of the most vulnerable people she’d ever met. I’m warmed that so many liberals thought the late William F. Buckley — annoying to me almost as much for his parody-worthy voice as his politics — was kind. I had never disliked John McCain, actually, but the news that he once woke his daughter Meghan up to excitedly tell her some gossip about the celebrity couple they both followed — J-Lo and P-Diddy — made me almost forgive his poor judgment in choosing Sarah Palin.

I’m heartened that Martha Stewart was a mensch to a low-level talk show assistant, and that Orrin Hatch earnestly asked Carly Simon her opinion of the rock songs he wrote. And if you are a fellow collector of these arcane Kumbaya-esque smile inducers, then you might agree that the three-weeks-ago news that John Boehner beamed proudly as he walked his daughter down the aisle to marry a Rastafarian was almost as joy-giving as a replay of your favorite Bob Marley song (here’s mine.)

Therefore, it was  stomach-turning to learn that multibillionaire David Koch — the fourth-richest man in America and a behemoth funder of right-wing PACs, who is currently making alleged moves with his brother Charles to acquire the Los Angeles Times and the Chicago Tribune — is exactly the hypocrite about “job creation” and the pass-it-on virtue of wealth once called “trickle-down economics” that I expected him to be.

Let me backtrack a moment. In case you missed it, Jane Mayer wrote an excellent piece in this week’s New Yorker about how a documentary by distinguished filmmaker Alex Gibney called “Park Avenue: Money, Power, and The American Dream,” based in large part on Michael Gross’s book “740 Park,” essentially caused Koch, a recent mega-patron and board member of New York City’s PBS affiliate WNET, to resign from WNET’s board and to cease his donations.

Gibney’s documentary, which aired on WNET last November via the “Independent Lens” series sponsored by a San Francisco-based consortium of staunchly independent filmmakers, was critical of Koch, who resides at 740 Park. Mayer’s piece traced the special courtesies that WNET President Neal Shapiro extended to Koch, inviting him to rebut or soften the portrait of him in the film. She also goes into detail about the chilling effect that fear of Koch’s money and power has had on the efforts to get another film about the Kochs, who are by any measure outsized infuencers of right-wing politics in America, to the viewing public.

I’m sure I wasn’t the only one unsurprised that, as Gibney himself expressed, “Money talks.” To be honest, I give WNET props for airing the documentary in the first place, which isn’t to demean its integrity, just to express a grim-and-getting-grimmer reality of American life. (Perhaps Harvey Weinstein or Michael Bloomberg can pick up the funding?)

But, to me, the most egregious lines Mayer wrote were these: “At one point [in the documentary], a former doorman — his face shrouded in shadow to preserve his anonymity — says that … the cheapest person [in the building full of super-rich cheapskates] was David Koch. `We would load up his trucks — two vans, usually — every weekend, for the Hamptons . . . multiple guys, in and out, in and out, heavy bags. We would never get a tip from Mr. Koch. We would never get a smile from Mr. Koch. Fifty-dollar check for Christmas.”

Let me repeat that: FIFTY DOLLARS’ TIP FOR CHRISTMAS, to this hard-working guy who toted barge and lifted bale for this multibillionaire every weekend. I gave $30 more than that to the cashiers who simply rang up my take-out sushi three times a week at my favorite seafood market.

The fellow-writer friends I’ve polled who live in New York in significantly more modest circumstances tip their doormen or supers, at Christmas time, considerably in excess of the distressingly small lump of coal Koch dropped in his doorman’s stocking. $900 to  $1,000  in apartment and service-people holiday tips (and more to them for special work provided during the year) is the name of our game. Decency and generosity and a responsible attitude toward the voluntary compensation that anti-tax folks are always screaming about: This is all part of a person’s humanity.

Decades ago, Frank Sinatra used to give $50 (that’s about $300 in today’s money) to his doormen, every time one of them held open his Manhattan apartment building’s  front door.  No wonder “All The Way” sounded so soulful.

In this week when journalists are rightly up in arms over the government’s accessing their phone calls to their secret sources, I salute the secret source (“his face shrouded in shadow”) — David Koch’s ex-doorman — whose words we all might do well to think of whenever a Citizens for Prosperity public service commercial comes on.

Sheila Weller is an award-winning magazine journalist and author of six books, including 2008′s New York Times bestseller “Girls Like Us: Carole King, Joni Mitchell, Carly Simon — And the Journey of a Generation.” She is currently working on “The News Sorority: Diane Sawyer, Katie Couric, Christiane Amanpour — and the Triumph of Women in TV News.”