This is true. While I appreciate all feedback, the cable and housing are brand new and I am 100% confident (through diagnosis similar to both SBinNYC's and FBinNY's suggestions) that the problem lies with the brake itself.

If adjusting the pivots entails tightening/loosening the nut & bolt that holds the spring, I will give this a try. I'm not sure what "lubricating the mechanism" entails, but it seems like friction is certainly a viable culprit. I will try something to alleviate this, but if anyone could provide some specifics I would appreciate it.