Comcast was supposed to have a solid broadband business to fall back on, but even that's in trouble.Comcast (CMCSA 1.58%) has been trying to find its way as linear TV declines, but investors always thought the broadband business would be a saving grace. That may not be the case, and with management considering the spin-off of some cable channels, things are getting desperate fast. Travis Hoium shows how quickly the business has declined in this video.*Stock prices used were end-of-day prices of Nov. 19, 202 ...