NEW YORK (CNNMoney) -- Weeks ahead of the premiere of a CNN documentary focusing on diversity in the tech industry, the charged issue is already generating sparks. A heated debate broke out on Twitter Wednesday night after a preview screening of Black in America 4.

Blogger-turned-investor Michael Arrington ignited a controversy with his comments about the visibility of minority-led companies. In the documentary, which airs November 13, Arrington talked about his difficulties finding African-American entrepreneurs to launch their ventures at his TechCrunch Disrupt conference -- and suggested he would accept almost any black entrepreneur, regardless of merit.









"There's a guy, actually, his last company just launched at our event, and he's African-American. When he asked to launch -- actually, I think it was the other way around. I think I begged him," Arrington told CNN's Soledad O'Brien.

"His startup's really cool. But he could've launched a clown show on stage, and I would've put him up there, absolutely," Arrington said. "I think it's the first time we've had an African-American [be] the sole founder."

It's a remark that didn't sit well with some in the tech community. Female and black entrepreneurs fired off tweets saying they didn't want to be treated any differently because of their skin color or gender.

"I don't want to be funded b/c I'm a woman, and I certainly don't want ppl to believe that's why I'm funded," wrote Katrina Stevens, co-founder of LessonCast, a training website for teachers.

Arrington, who has not yet seen the finished documentary, mounted a vigorous defense on Twitter. About two-thirds of his Crunchfund investments so far have gone to female or minority-led ventures, he said -- and the entrepreneurs landed the cash solely on the strength of their ideas.

"We funded 100% of the black founders who've pitched us (2). And it had nothing to do with skin color," Arrington wrote.

But he also maintained that women and minorities no longer face any extra obstacles in the tech industry. In his words: "there's zero race or sex bias in silicon valley."

Dozens of commenters fired back against that remark.

"Even after all this time, still amazes me when @arrington presumes to speak as an authority on the experiences of women & people of color," Anil Dash, a prominent blogger and veteran of the startup scene, tweeted back at Arrington. "You're saying 'women and people of color never have issues in SV' but how could you possibly know that?"

There's plenty of evidence that active -- if often subconscious -- bias plays a role. Legendary investor John Doerr made a telling, offhand remark a few years ago at a venture capital conference. He observed that the "world's greatest entrepreneurs" are almost all "white, male, nerds who've dropped out of Harvard or Stanford."

"When I see that pattern coming in -- which was true of Google -- it was very easy to decide to invest," he added.

"I have personally experienced the discrimination and bigotry," tech industry researcher and writer Vivek Wadhwa tweeted back at Arrington. "Know what it feels like and how it discourages."

In CNN's documentary, The New Promised Land: Silicon Valley, Wadhwa made similar remarks.

"When I did raise venture capital, my buddies' advice to me was, they said, 'Get a white guy to be your front man.' And I did that. I hired a very impressive, six-foot-tall, impressive, polished white guy, and let him do all the talking," Wadhwa told a group of aspiring entrepreneurs. "That's the way the system works here. You might as well understand it, and then use it to your advantage."

But Arrington made a second point on Twitter that touched nerves: He thinks the pendulum has swung the other way, and that female and minority entrepreneurs now get an extra boost from investors "dying" to diversify their portfolios.

That kicked off a wide-ranging discussion on Twitter. Is there a "negative" bias in Silicon Valley? Are women and minorities given an extra edge because the tech scene needs more diversity?

And, taking the issue a step further, where are the roots of the problem? Is it that venture capitalists shy away from funding minorities, or are there too few minorities entering the field?

"The problem isn't there is barriers, the problem is that they aren't entering the field in the first place," college student and self-described "startup enthusiast" Mikey Tom opined.

The New Promised Land: Silicon Valley, the fourth installment in CNN's Black in America series, will premiere November 13 at 8 p.m. ET. Watch the trailer on CNN.com, and check out CNNMoney's full coverage of the project.