Illinois is capable of defeating Northwestern.
If Illinois played more than one good quarter against Iowa, they would have defeated Iowa. After the 1st quarter of the Iowa-Illinois game, I did not know how Iowa could possibly defeat Illinois, but then the Iowa o-line started blowing Illinois' D-Line and linebackers downfield. The Iowa defense started taking care of business, too.
Illinois may have gained enough insight to understand they have the capability, but need to keep up the confidence, and pressure for an entire game.