Eight years ago, Hillary Clinton lost the Iowa "ground game," and her presidential aspirations. Not this time. 

Hillary Clinton's campaign organization covering Iowa's 99 counties was said to be one of the best ever, and it got the job done on Monday, propelling the former New York senator to a narrow victory over the insurgent Bernie Sanders: 49.9% of caucus-goers vs. 49.6%.

"Winning in a state where she came in third just eight years is going to be a real boost for her campaign," said Anita Dunn, a Democratic strategist at SKD Knickerbocker. "She had run there before, she had a superior organization for much of the year, and what's important to see is that in a very tough race with a progressive group of voters, she has been able to hold her own."

That so-called "ground game," an integral part of winning any election, but more so in the time-consuming caucuses, was the top reason an overwhelming number of party strategist and activists, 87%, surveyed in a Politico poll, published just prior to the caucuses, predicted that the former secretary of state would take home first prize in the first-in-the-country electoral contest.

Ultimately, it was Clinton's organization, born of many months in the state and ample resources, that combined a large and experienced staff with a media operation that more than matched Sanders surprisingly effective television commercials. 

The Vermont senator, whose message about the root causes of income inequality resonated with much of the state's Democrats, just about kept pace with Clinton's media campaign. In an analysis of political advertising data compiled by the Political TV Ad Archive, the National Journal reported that between Dec. 1 and June 30, Clinton's advertising totaled 5,268 minutes compared to Sanders's 5,011 minutes.

The number of unique spots released by Clinton and Sanders was just about even. Clinton at 21 and Sanders at 20, according to the analysis.

Of course, Clinton and the main PAC aligned with her, Priorities USA, spent more  money early, opening store front campaign offices throughout the state. In all, Priorities USA reported last week that it had raised $51 million stretching from the start of 2015 to the end of January.

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Though he began the campaign at a distinct financial disadvantage, Sanders's campaign was able to raise about $33 million during the final three months of 2015, mostly from small contributions, and another $20 million during January.

As might be expected, Clinton and Sanders supporters split along income lines with those in households making more than $100,000 a year siding with Clinton, and those making under $50,000 annually going with Sanders, The New York Times reported citing exit polls conducted by Edison Research.

Campaigning hard in Iowa's college towns on its eastern side, the Sanders campaign also made a big bet on political advertising. Beginning in November when Sanders began TV advertising in Iowa, his campaign ads aired 2,531 more times than those from the Clinton campaign, according to The Times.

Having been beaten soundly by Barack Obama's savvy campaign in 2008, Clinton knew full well the importance of identifying and getting caucus voters to their appropriate locations. Eight years ago, Clinton was beaten in Iowa by both Barack Obama and former vice-presidential candidate and North Carolina senator John Edwards.

"What you're seeing this evening, in an exceptionally close race, is a Democratic Party that has two candidates who represent many ways shared policies but radically different approaches on how to get there," said Dunn, who served as Obama's White House communications director during 2009. "Iowa was away going to very close but the Clinton camp showed they learned their lessons from 2008."

Sanders's campaign, which made income inequality its defining mantra, posted the most-watched political ad in Iowa, a punchy indictment of political spending by large banks that dominate the U.S. financial system. Even then, Clinton's ad explaining how she would seek to bridge the U.S. "wage gap" came in fourth, according to the National Journal.

The campaign moves to New Hampshire, where Sanders is well known, given his more than three decades of political activism in neighboring Vermont. Yet Clinton's performance in New Hampshire could surprise observers, who have been forecasting a Sanders victory based in recent polls.

Neil Levesque, a longtime observer of that state's political machinations as director of Saint Anselm College's Institute of Politics & Political Library, said late last month that in New Hampshire, Hillary Clinton's "ground game is good, her staff is the best I've ever seen, and I've seen them all."