An eye-popping $4 million was pumped into Illinois’ 17th District congressional race in its final 20 days, according to an analysis of finance reports, bringing the total cost of the campaign to $13.9 million, by far a record for the Quad-City area.

Democrat Cheri Bustos won a convincing victory Nov. 6 over Rep. Bobby Schilling, a fresman Republican who was seeking to hold onto a district that had been in Democratic hands for nearly all of the previous 30 years.

The battle between the two turned into a magnet for outside spending, and reports filed this week show just how expensive it got.

In reports that covered the last three weeks of the campaign, Bustos and Schilling spent more than $1.2 million between them. But that paled in comparison to the $2.8 million that their political parties and outside groups poured into the race’s final days.

The bulk of the late outside spending came from the political arms of the House’s two parties, the Democratic Congressional Campaign Committee and National Republican Congressional Committee, as well as the Karl Rove-founded Crossroads GPS advocacy group. The DCCC spent nearly $928,000 in the last three weeks, while the NRCC spent about $718,000. Crossroads spent $518,000.

Bustos, meanwhile, outspent Schilling in the last three weeks, the reports said. She spent $673,823, while Schilling doled out $559,336.

Overall, Schilling spent close to $2.6 million for the two-year election cycle, while Bustos spent nearly $2.1 million. Independent expenditures came in at nearly $9.3 million.

It’s not uncommon for the biggest expenditures to come in a campaign’s final few weeks. But the 17th District was a record-setter. The previous high for a Quad-City congressional cycle was $9.5 million in 2006 in Iowa’s 1st District race between Democrat Bruce Braley and Republican Mike Whalen.

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Much of the spending in the 17th District’s final days was on television advertising, the bulk of it critical of each of the candidates.

Across the river, the spending amounts were far tamer. Rep. Dave Loebsack, D-Iowa, who defeated Republican John Archer, spent $444,001 in the final 20 days, while Archer spent $203,824. That brought them to overall totals of just over $1.5 million and $951,000, respectively.

Outside spending in the race for the general election — not counting a small amount spent in the Democratic primary — totaled roughly $800,000. That brought the overall total to more than $3.3 million. The bulk of the outside spending came from the NRCC in television ads criticizing Loebsack. None of it was spent in the last three weeks.