This wasn't about money at all. This was about a weak candidate the Dems ran against Walker, a shrinking union membership, and basic common sense in the voting bloc. You had an entire network behind you, two if you count CNN, too.
Republicans could outspend you, 8-to-1, in most blue states, or vice versa in red states, and that wouldn't change an election much. Wisconsin is supposedly a blue state, so what's up?