I deny that Obama was given better treatment.
Yes, Obama's drug use was largely ignored -- because it was over 20 years ago.
McCain's membership in the Keating Five was also largely ignroed -- because it was over 20 years ago. (This despite the parallelism to the current problems in the financial sector.)
The press reported on the problems and in-fighting in McCain's Campaign. Obama had no such in-fighting to report.
The press reported on the open hostility toward Obama at McCain rallies. Obama's rallies had no such open hostility. Further, the media refrained from harping on McCain's "categorical" pride in the people who attended his rallies when said people made news.
Obama happened to have rallies with tens of thousands of people. That happens to be positive news.
McCain happened to have rallies with tens of thousands of empty seats. That happens to be negative news.
What I'd like to see is a look only at how the candidates positions were covered.
Were the press more hostile to McCain's proposed tax structure than Obama's? All I recall is that there were both found to be lacking in the deficit-management department.
Were the press more hostile to McCain's health proposals than Obama's? I recall seeing that a $5000 credit won't replace the $12000 that's spent by employers for a typical family of four and that mandating full employer coverage of health premiums would result in either less hiring or lower wages. Both are reasonable critiques.
I don't recall a bias for either candidate's positions on any subject.
McCain and his people did, however, do a lot of things wrong during the campaign. Obama and his people did very little wrong, and what was screwed up was covered (however, it was also corrected quickly by the campaign, and thus became non-news quickly).
For example: When Biden appeared to claim that the official position of the Obama campaign was against coal power (and the statements he made on the rope line still appear to be making that claim), the campaign quickly corrected the postion and Biden himself corrected it at every turn.
On the other hand, when Palin "went rogue" by going off-script, McCain's people magnified the problem by bitching about her to the press -- repeatedly. The wardrobe question was a dead horse quickly, and Palin making an unprompted clarification that the clothing did not belong to her was mild, appropriate (since the attacks were against her personally), and did nothing to make that non-issue stick. The attacks by McCain's advisers making known that the person they were fielding as their VP candidate had a script and that they, the McCain advisors, believed that they were the ones to tell Palin what to say and what not to say created a very real negative news story..