I would place the lion's share of the blame on Taft. Then the fact that the Republican establishment didn't back him.
His nomination was a real conservative grassroots effort, but he didn't get the support he needed, and he couldn't pry himself away from Taft's disaster..........even though he fought it all the way.
It's a real loss for Ohio. And Strickland..............ARRRGHHHH!!!!
There were several factors in Ken Blackwell's loss. Yes, the Taft scandals were a drag. And possibly the loss of early support from the party was evident too. But that was early and there was a massive amount of healing that took place after the primary between Blackwell and the party.
The factors that also brought Blackwell down were his too cozy relationship with the religious right (too many non evangelical, but republian leaning voters are afraid of folks like Rod Parsley and the movers and shakers of the religious right). Blackwell wasn't seen as a maverick, but rather a bully. His persona is one of someone who doesn't play well in the sandbox. Also blame Blackwell for only playing to his base. He never once seriously attempted to make a case to independents and non social issue voting conservatives. In that manner he was divisive.
You had mentioned his strength in Richland County, yet he lost by almost 10 percentage points. In republican rich Delaware County in Central Ohio, he lost there too. I think there are only three democrats in Delaware County (ok joking, but it is a very republican county).
You've got to look at the popularity of President Bush. That too was as much of a drag as Taft.
Finally, if it was all Taft, then all the republicans would have lost with a similar margin as Blackwell did in the statewide races. They didn't. And one republican even won. The candidates who did most poorly were the ones most closely linked to social conservatives.
I've got to wonder where you and LS kept coming up with the information that the race was competitive. The only thing I can think of is you were either talking to like minded people only or the Blackwell campaign was feeding you information that wasn't statistically backable. Or you folks were trying to maintain a positive spin and blowing sunshine.
Ken Blackwell was the values voter version of the perfect candidate. We've been told too many times that if such a candidate was put on the ballot and play to those themes, they would win hands down. It didn't work.