I'm not so much interested in the cascade of bad stories that have fallen on Cain - the sexual harassment and illegal campaign funding stories. What I'm interested in is where they came from and why now.
The Romney campaign. Just like the Perry niggerhead story before it. The Romney campaign is loaded with money for opposition research, they have dossiers on each of his opponents that would choke an elephant. Romney has a stable of old school political consultants who believe in the power of the well timed leaked smear.
The order the stories broke is also old school. Start with the big hit, sex if possible. Then, just as they are starting to respond to the first attack hit them with a second smaller strike. It's called piling on.
Cain and Gingrich have a one-on-one debate scheduled for this coming Friday. If it comes off well (and it probably will look a lot better than the cattle call debates) it could mark a seismic shift in the campaign dynamics, a shift that in no way would be good for Romney. Breaking the news now gives it enough time to sink in without allowing time for the stories to be vetted. If the Friday debate doesn't mention sexual harassment (and it won't) then Romney friendly reporters will dismiss the debate as a non-event and that will become the zeitgeist of the week.
I won't call Romney's campaign brilliant for this move because it is just Smear Tactics 101. I can understand why Romney is so terrified of the Cain-Gingrich debate that he would waste both of his best weapons against Cain so soon. While Cain won't take the nomination if he beats Romney early Cain can kill off the Romney campaign.