WASHINGTON -- After several rounds of painful soul searching, Washington-based progressives are comparing notes on Ilya Sheyman's stunning open-primary loss to a fellow Democrat, businessman Brad Schneider, in Illinois' 10th congressional district Tuesday night.

Sheyman, who rose through the ranks of MoveOn.org, outraised Schneider, was leading in polls and had the enthusiastic support of the pillars of the online progressive community, yet collapsed in a heap and lost by eight points.

"I'm flabbergasted. I'm embarrassed. This is the biggest screw-up electorally that I've ever been involved in," said one progressive activist still sorting through the wreckage.

Sheyman had national attention and the backing of the Progressive Change Campaign Committee, which raised more than $130,000 from donors; Democracy for America, the group that sprung from Howard Dean's grassroots presidential campaign, which kicked in another $80,000; and USAction, which sank around $35,000. The Communications Workers of America joined with MoveOn and USAction to create an independent expenditure (IE) arm that spent roughly $100,000 on the race. Sheyman claimed to have a 600-person army of volunteers, and in the days leading up to the election, they knocked on over 12,000 doors and made over 15,000 phone calls.

Public polls leading up to election day had Sheyman cruising to victory, leading to a public self-flogging after the election from PPP, the Democratic-leaning firm that missed so badly. People close to the campaign, however, say that private polls done by other firms were showing similar results.

So what happened? HuffPost spoke to people involved with the campaign from every direction, and this is what we heard:

Turnout.

Expanding the electorate is the goal of every insurgent, as a campaign envisions fired-up voters shaking off their apathy and swarming polling stations. People close to the campaign say they expected at least 50,000 people to come out, confident in their people-powered movement. Sheyman himself made the same prediction to The Huffington Post on Tuesday before the polls closed. But only 32,886 voted. Low turnout made up largely of people who always vote in primaries benefits the establishment candidate, who in this race was Schneider, who had the backing of moderate House Minority Whip Steny Hoyer (D-Md.) and former Illinois congresswoman Melissa Bean, who was a member of the moderate New Democrat Coalition.

But the district is home to roughly 15,000 MoveOn members, Sheyman's campaign repeatedly reminded the media, and there were the 600 volunteers. It was 85 degrees and sunny. Why didn't the enthusiasm translate to greater turnout?

"Sometimes we're guilty of being inside our own echo chamber, reading our own blog posts," said Tim Carpenter of Progressive Democrats for America, which contributed volunteers to the campaign. "Sometimes we fall prey to our own press clipping, our own chest pounding ... We need to have an honest assessment about what works."

Adam Green, the head of the PCCC, told supporters in an email that "[i]t was predicted that as many as 60,000 people would vote." He referred questions on turnout to the campaign. A person involved with the IE, in defending the high estimate, pointed to 2010 turnout figures for a district that was similar to the 10th before it was redrawn.

But in 2010, heated Senate and gubernatorial campaigns drew more voters to the polls. With no significant statewide race on the 2012 ballot, it would make sense to expect -- as the Schneider campaign says it did -- that turnout would be lower.

All of this may sound trivial, but accurately predicting the turnout universe is the foundation of a successful campaign. Strategy is based on that assessment, and if the foundation is off, resources will be wasted targeting the wrong voters. A source close to the Schneider campaign noted that they sent more than twice as much mail to targeted voters, while Sheyman burned resources on a larger field.

"There is a real danger in believing your own hype and being ideological about how to win. You still need to count every vote one at a time," said a progressive operative.

Negative advertising backfired.

A stereotype of D.C.-driven campaigning is the negative ad, and Sheyman's backers didn't shy away.

Washington insiders see negative campaigning as a calculated and sophisticated move, but it's hard to control, especially among two Democrats. Several local Democratic officials jumped in and endorsed Schneider after Sheyman went negative, just as the GOP presidential candidates were crisscrossing the state slinging mud at each other.

Schneider campaign strategist Mark Bergman said that while these progressive groups gave Sheyman money and on-the-ground help, their presence may have turned off voters in the district.

"I think the fact that they were out of state, that a lot of Ilya's support came from out of state, had an impact," he said. "I also think the fact that they were simply saying things that were over the top and false had an impact in having a backlash against Ilya's campaign."

One attack that reflected particularly poorly on Sheyman was an attempt to paint Schneider as a conservative Blue Dog Democrat. Howard Dean said Schneider was "basically a Blue Dog, a Republican." Schneider's campaign hit back that he didn't identify with the Blue Dogs and was never endorsed by them.

"Ilya's negative advertising is full of overt distortions," state Rep. Karen May (D-Highland Park) told Deerfield Patch just a week before the election. "I've decided to vote for Brad Schneider. What Ilya's doing is not good for us (Democrats). I'm not alone. I'm hearing this from my friends."

The candidate was flawed.

Any 25-year-old starts with a disadvantage. For Sheyman, it was compounded: He looks like he just got bar mitzvahed, an observation made to HuffPost multiple times. And, as you might expect from a man that young who's interested in running for Congress, he often came across as socially awkward, said several people who know him well. "I think he was really challenged to connect with his audience. He's sort of an awkward kid," said one progressive who knows the candidate.

"Ilya's a great guy. He's all of our friend, all of that," the activist added. "But that shouldn't be a good enough reason to make him the symbol of the progressive movement when the stakes are so high. It's a loss that actually impugns all of our collective credibility to be able to run and win seats."

Sheyman said he respected the honesty, and admitted that he is "an imperfect messenger" for the progressive cause.

"People are free to judge how I was as a candidate," he added. "One thing I did see is we did over 100 house parties across the district, talked to thousands of people, energized 600 volunteers. Something we did worked."

The infrastructure is outdated, and the focus is off.

Several leading progressives told The Huffington Post that Sheyman never should have run. They said they had doubted his chances of winning, and that some had tried to talk him out of it. Yet his impulse to immediately campaign at the federal level, and the national group's rush to back him, is symbolic of a myopic focus by progressives on the national stage.

"Ilya as a very persistent ideological progressive could've probably done more in the state senate in the next years than he can in a hyper-polarized Congress," said Ilyse Hogue, a former top MoveOn official who knows Sheyman.

For decades, conservatives quietly elected like-minded ideological foot soldiers to local school boards, town councils and state legislatures as ways to build up their power bloc and extend conservative ideas throughout American society. The rash of ultra-conservative legislation sweeping state capitals didn't come from nowhere. The hard work has flowed up, teaching a generation of conservatives how to take and leverage power.

"We don't think like that," said Hogue. "And our national groups think at the national level, and think state office goes to state groups, which is to our own detriment. We don't learn from what the other side has done, which is look at it as one giant chess board, and how we advance over the long term."

At least he pushed the conversation to the left.

When Bill Halter challenged incumbent Sen. Blanche Lincoln in Arkansas' 2010 Democratic primary, progressives quickly flocked behind Halter, seeing it as the best opportunity to throw out the Blue Dog lawmaker. When Lincoln won, progressives were disappointed, but still saw the victory as a win. After all, she ended up making gutsy, progressive financial legislation a centerpiece of her campaign. She shocked Wall Street by proposing robust regulation of derivatives in the middle of the reform debate, a move that ultimately strengthened the final bill in major ways. (Lincoln later lost a general election to Republican John Boozman.)

Sheyman's supporters argue that the same dynamic was in play in Illinois' 10th district.

"If you look at [Schneider's] record, he was just an Israel guy, that was his thing," said Daniel Mintz, who manned the campaign for MoveOn. "Because he was in a competitive primary, he ran a campaign that was incredibly progressive. Every piece of mail -- and he dropped a lot of mail -- had the word progressive plastered on his forehead. He dropped doorhangers that implied that the president endorsed him. His platform was all about the government putting people back to work, taxing the rich, and protecting Social Security and Medicare. So basically he embraced the 99 percent platform, which is all about rebuilding the middle class. So I think one of the lessons, win or lose, is that primaries work if you want to push people toward the edge, whether that's right or left."

"I think what this primary showed is that you can win by running as a progressive," said Sheyman. "If you stand up and run for progressive values, you can shift the conversation and get every other candidate to run on those same progressive issues."

"It's not about the loss, it's about building the progressive movement," added Linsey Pecikonis, deputy communications director at DFA, which was the first group to endorse Sheyman. "You're going to have to hear people from all sides say, he should have done this, he should have done that. But he ran the best campaign that he could, and I think that he really built a solid foundation."

A progressive could still win the general election.

Illinois' 10th congressional district is a top target of the Democratic Party in 2012. Democrats need to pick up 25 seats to take control of the House of Representatives, and Rep. Steve Israel (D-N.Y.), chairman of the Democratic Congressional Campaign Committee, has put the district on its "Red to Blue 2012" list. The district leans Democratic and went for President Obama and Sen. John Kerry (D-Mass.) in the last two presidential elections, although it's currently represented by Rep. Robert Dold (R-Ill.) and has a history of splitting its tickets.

Mintz said that if Schneider wins and legislates the way Sheyman forced him to campaign, progressives will have won. In a call with reporters on Wednesday, Israel said Sheyman really "revved up" the grassroots and acknowledged that the district would have been put on the DCCC's target list regardless of who won the primary.

Sheyman, for his part, has no regrets.

"I think we made a tremendous difference in making sure the conversations for the past year, in one of the most important swing districts in the entire country, were about how you put people to work, how you restore fairness to our tax system, how do you invest in our economy. I think we played a constructive role," he said.

He said he wants his supporters to get behind Schneider -- while continuing to hold him accountable for standing up for progressive values.

"Part of our goal has always been to take back the House," he said. "This is the most Democratic seat in the whole country held by a Republican. It's a seat we have to win to take back the House. I expect our supporters to help Brad win this seat."

CORRECTION: An earlier version of this story reported that the Sheyman campaign relied on turnout figures drawn from the 10th congressional district as it was drawn prior to this election. In fact, the campaign was able to reconstruct the new district and relate it to prior years.

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