The 61-year-old self-described "failed writer" and amateur Web journalist helped create two of the most unexpected moments in the 2008 election -- most recently on Monday, when she recorded former President Clinton's fiery denunciation ("slimy," "dishonest") of Vanity Fair writer Todd Purdum.
That scoop came six weeks after Fowler rocked the Democratic race for president by reporting (from a "closed press" fundraiser in San Francisco) Barack Obama's now infamous discussion of "bitter" small-town Americans who "cling to guns or religion or antipathy to people who aren't like them."
The latest incident cemented Fowler's place as the unlikely face of the new-media revolution that is remaking presidential campaigns. Online videos can dominate the evening news. Or an unpublished novelist "with absolutely no journalism training" can alter the national debate.
In her first public remarks on Clinton's outburst, Fowler attributed her success to persistence, serendipity and an acknowledged flouting of the old rules of mainstream journalism.
"Of course he had no idea I was a journalist," Fowler said by phone from her Oakland home, recalling her close encounter with Clinton for "Off the Bus," a citizen journalism project hosted by the Huffington Post website. "He just thought we were all average, ordinary Americans who had come out to see him. And, of course, in one sense, that is what I am."
Fowler said she felt empathy for Clinton before and after he shattered the "elegiac" final hours of Hillary Rodham Clinton's presidential campaign with his agitated statements.
"He is exhausted. It's the end of the road. He realizes it might be his last day campaigning," Fowler said in explaining Clinton's three-minute eruption. "He does not have the impulse control he once had. And, at that time at least, he still could not understand or appreciate why Barack Obama is so popular."
The Clinton swing through South Dakota began like many others for Fowler -- with long days scrambling after the candidate and prolonged nights filing dispatches "in my pajamas and pashmina in the business center of some Hilton Garden Inn."
She was on hand when he addressed hundreds of voters in Milbank, waxing about what he said "may be the last day I'm ever involved in a campaign of this kind."
Fowler left after the rally, then turned back on the longshot hope that she might be able to slip him her business card and request an interview with his wife, who was just days away from ending her campaign.
In the jostling crowd surrounding Clinton, however, Fowler dropped the card. She only managed a handshake and went blank -- her mind suddenly void of any worthwhile question.
"I missed my moment," Fowler thought, discouraged. But Clinton, ever the ebullient retail politician, reached out a second time. Fowler's mind flashed to the Vanity Fair profile, which accused Clinton of dirtying his legacy by running with unsavory friends and business associates.
"Mr. President," Fowler asked, "what do you think about that hatchet job somebody did on you in Vanity Fair?"
A tape of the incident has Clinton describing the magazine piece with escalating anger, even as admirers seemed to grow uncomfortable and tried to steer the conversation to lighter ground.
Fowler, at one point, interjected that Purdum, the author, is married to onetime Clinton Press Secretary Dee Dee Myers. Clinton retorted: "Yeah, that's all right. He's still a scumbag."
A man on the rope line tried to distract Clinton with a personal appeal. "I grew up in Hope too," the fan said. "Hope, North Dakota."
Clinton wouldn't be distracted. He continued on about the magazine and Purdum: "Let me tell you, he's one of the guys, he's one of the guys that propagated all those lies . . . " Clinton ended the harangue by assuring, unpersuasively: "It didn't bother me. It shouldn't bother you."
Fowler captured the whole thing on her candy-bar-sized digital recorder, which she says she held in plain view. She rushed to download the audio, slowed on her way to her hotel only by a state trooper in front of her who insisted on "going 78. I would have been going a lot faster than that."
She has spent about a year reporting from the field for the "Off the Bus" project, which was designed to offer outsiders the chance to write about the candidates and their campaigns.
Fowler had become excited about Obama, so she filed her first dispatches from the Illinois senator's campaign stops. Unlike traditional journalists, she openly reported her preference for Obama (while she occasionally tweaked him for arrogance or elitism).
Some Obama supporters became so angry over her posting of the "bitter" comments that they accused Fowler of being a Clinton operative. She says she received hundreds of angry e-mails.
Nonetheless, she said she will "certainly" vote for Obama in November, even though she now sees him as more flawed, like all candidates. "I don't think I'm dazzled anymore."
And fair warning to another candidate who might soon discover a tiny, unassuming woman with a question on the rope line.
"Next," Fowler said, "I'm going out with McCain."