An interesting analysis has been done by www.fivethirtyeight.com on the scale of President-elect Obama's victory. It is the second largest of all time in terms of popular vote as a percentage of population. Obama's 68.7 million votes (the largest ever) represented 22.62% of the population; only Ronald Reagan's landslide 1984 victory represented a higher amount.
In terms of percentage of the vote, Obama's 53% share is comparable to that of George H W Bush but greater than any freshman presidential candidate since Eisenhower in 1952. Only Reagan in 1984 and Lyndon Baines Johnson have won a greater share of the vote. By historical standards this victory was huge. It was not a wipe-out but it was a landslide.
Post script: An interesting perspective on Obama's foreign policy by E.J.Dionne where he makes a useful comparision with the policies pursued by George H W Bush is worth a read. Robert Gates was a senior figure in that administration.