This is a pretty good analysis of how Doug Hoffman lost an election he could have won. The fact he got hung up on local issues is ironic since his opponent was no better informed, but was seen as more glib and thus never challenged. An extra aside from yours truly....the race was created by the White House who had picked the candidate and devised the strategy before they created the vacancy. They had the sophisticated field canvassing effort in place and would have likely beaten Scozzafava if the Hoffman phenomenon never occured.
The Democrats pivoted to play in a race they never could have anticipated and won the end game simply by showing their guy to be more mainstream and reasonable to the few voters in play the final few days. The big swing came in the western and southern ends of the district where Hoffman should have won big, but didn't.
American Thinker: Who lost NY 23 for the GOP?