Blagojevich will narrowly pull this off due to the extreme incompetance of the Illinois GOP. When your opponent's campaign is being ran by people dumb enough to think bringing Alan Keyes in is a good idea, well that says it all.
I don't think they *wanted* to bring Alan Keyes on... they just didn't have much of a choice.
There were other people offering to run. They also could've just left Ryan's name on the ballot and considered the race done. They had absolutely no chance whatsoever of winning the seat at that point anyway, no reason to bring in a carpetbagging nutjob who did nothing but massively hurt them downticket, and possibly cost them a House seat.