WASHINGTON — Whatever happens in next month's election, Democrats from different wings of the party are sure to fight over what the results mean for how the party should position itself in future elections.

One of the top races likely to be parsed over is a congressional contest for a swing district in Omaha, Nebraska, where a progressive first-time candidate upset a moderate former congressman in a Democratic primary in May.

Non-profit executive Kara Eastman — who was profiled in September in NBC News.com's "Mad About Trump" special report — was one of only two insurgents to beat a candidate backed by the Democratic Congressional Campaign Committee, the party’s official campaign arm, in a battleground district this year.

Immediately, her campaign attracted national attention as progressives hoped to prove their ideas could win in the heartland, while moderates warned she was too liberal for the district.

But in the general election, national progressive groups have not invested heavily to support Eastman and the party's establishment has also largely stayed on the sidelines in what is likely to be most expensive race for that district in history.

That's allowed Republican attack ads on Eastman by outside groups like the Conservatives Leadership Fund to go unanswered, even though Eastman's campaign has kept pace with that of her opponent, Rep. Don Bacon, raising $2.4 million to his $2.7 million.

"Kara has made it clear from day one that she wants to run a positive campaign and part of that is she hates negative ads, so she's glad she has'’t seen any purchased in her name by outside groups," said Heather Aliano, Eastman's spokesperson. "She's very happy with the support she has received and has all the resources she needs to be competitive."

But some progressives in Nebraska and Washington have expressed frustration about the lack of support and worry it could discourage potential candidates from mounting insurgent progressive bids in the future if they think national liberals won't have their back.

"While I'm optimistic about the work we're doing, it's frustrating that other national groups aren't following our lead and investing in the face-to-face conversations that we know will result in Democratic victories here in the heartland," said Alex Morgan, the executive director of Progressive Turnout Project, which says it has spent $210,000 supporting Eastman, including by hiring 10 Omaha-based field staffers.

The Eastman race slipped down both parties' priority lists as Bacon seemed to solidify his position, with the Cook Political Report now rating the contest as "lean Republican." But some Democrats believe earlier support for Eastman could have put her in a better position heading into the home stretch.

According to FEC independent expenditure reports, outside group have spent only $54,000 supporting Eastman and seemingly none opposing Bacon. That’s less than a single $66,000 ad buy this month made by one bipartisan outside group, With Honor, supporting Bacon.

Those independent expenditure figures do not include help provided directly to the campaign, such as PAC donations, joint fundraising emails, or staff support, and they do not include outside activity that does not directly reference either candidates' name. For instance, the Progressive Change Campaign Committee helped Eastman’s campaign raise over $70,000 and sent staff.

But for comparison, significantly more money has been spent just over the border from Omaha, either attacking Rep. Steve King, R-Iowa or supporting Democrat J.D. Schotlen — about $200,000 — even though that district is consider far less winnable for Democrats than Nebraska's 2nd.

More help is likely coming soon, as several progressive groups are in the process of preparing an ad campaign for the final week of the election that they hope will provide a strong a closing argument for Eastman.

For all the successes progressive insurgents have had in attracting attention and extracting concessions from the party's establishment this year, they have yet to build an infrastructure that can spend big money to support their candidates in general election campaigns, the way right-leaning renegades did during the Tea Party movement.