I think it is an interesting research question to ask why didn't Republican staff get and use this information in a timely fashion? As I understand it, Rev. Wright's racist anti-American comments were not hard to find. They were being sold on a CD in his church's bookstore.
My theory is that Republicans do not have enough journalists on their side. Republicans, who value business success, have a culture which does not encourage young people to become journalists. Republican political culture, after all, doesn't encourage politics as a career either.
Democrat party culture, in contrast, values young people who become low paid, hungry stalkers, scouring public records and websites to find damaging information about various Republican party candidates.
Republicans are at a great disadvantage because they do not have teams of volunteer reporters following up on tips. Remember the case of Dan Rather. One of his producers, Mary Mapes, thought she had documents damaging to President Bush's campaign. So she leaked this information to Joe Lockhart, a senior official in the John Kerry campaign. Mapes even offered to put her source, Bill Burkett, in touch with Lockhart.
Normally, we think of our biased media as simply twisting the story about Republican ideas and policies. We usually don't take into account the enormous resource these reporters provide to Democrat party campaigns...especially in terms of opposition research.
Even now, I think it is surprising that Sen. John Edwards managed to endorse Barack Obama before the news of his affair reached the general public. He was cheating on a wife with cancer who was covering up for him.
A balanced two-party system means that Republicans will need to invest extra resources in maintaining its own eyes and ears. I'd expect the Republicans to invest additional resources in efforts to make sure that who ever first discovers the bad news about the next Obama administration scandal knows who to call to get this information to the party officials, candidates, and appropriate news sources. Until then, Republicans will be in a disadvantaged situation caused - in part - by the pro-entreprenuerial values they hold dear.