Surprised, but not really. Most re-elections have Presidents winning by larger margins than the first time. Nixon, Reagan, Clinton, Bush. Obama losing electoral votes was an aberration.
I should note, in 2004 I was predicting Bush to win what he won (but I added Wisconsin so that made me 10 electoral votes over the actual result), but Democrats were sure that "this time" they'd defeat Bush. He lost the popular vote, his approval rating was constantly "under 50" and the economy was shaky due to his policies.
Not only did he win the popular vote the second time, but despite all of that, and an increasingly unpopular war, and all the changes we had gone through from the rise of social media to jetliners crashing into iconic skyscrapers...
....literally only three states changed. Bush picked up two Gore states (NM, IA) and Kerry picked up one Bush state (NH).
Same in 2012. "This time" we're gonna beat Obama. Enthusiasm. Polling.
One state flipped. North Carolina went to Romney. Nothing else. End of story.
The bottom-line: It's possible that we can have all the hoopla, and then see Biden hold the Hillary states, maybe add one, but still lose the election. It's very possible.
It is possible, however, one key difference between Bush/Obama and Trump is that Bush and Obama, despite their occasional unpopularity, still were popular, and were also personally popular. Trump on the other hand has remained unpopular and personally unpopular his entire presidency.
