Republican Rep. Cory Gardner will move to the Senate in January, replacing Democrat Mark Udall, despite being outspent.
Campaign Finance 2014
The incumbent Democrat has raised nearly $5.4 million for his campaign, while his Republican challenger has raised about $1.7 million.
Most of the ads scheduled for Sunday's game will target the U.S. Senate race in Colorado.
About 450 major donors – those giving at least $1,000 – eclipsed the amount of money contributed by 14,000 smaller donors.
A super PAC operated by the Ricketts family is the latest outside group duking it out on TV in one of the hottest U.S. Senate races in the country.
Republicans are spending more, but Democrats have more ad spots scheduled.