Santorum outgunned 7 to 1 in Illinois, 21 to 1 in Chicago media market

Rick Santorum’s campaign and super PAC have been outspent by a margin of 7 to 1 in the Illinois primary, with forces supporting Mitt Romney shelling out a total of about $3.7 million on the airwaves, according to a GOP media-buying source.

Romney’s campaign has spent $1,117,704 million in Illinois while the super PAC Restore Our Future has put in $2.556,353 million.

The Santorum campaign spent a comparatively modest $219,961 and the super PAC backing Santorum, the Red White and Blue Fund, put in $312,150.

The gulf was even more enormous in the crucial, expensive Chicago media market. There, Romney’s campaign spent $710,158 and his super PAC spent $1,367,125. The only pro-Santorum spending was $97,119 from the campaign, the same source said.

That amounts to a spending disparity of 21 to 1 in Romney’s favor.

Santorum narrowed the difference marginally in the last week of the race: his spending came all at the end, while ROF started advertising in Illinois around Super Tuesday on March 6. Cumulatively, the Romney spending appears to have taken a toll.