Political commentators in France and Germany registered surprise at Obama's underwhelming performance, saying the election could be much tighter as a result.
"Obama showed a lack of desire to be president, which could put him on shaky ground as a presidential candidate," said liberal German news magazine Der Spiegel.
"It's now clear that to get back into the White House the U.S. president needs running shoes, not flip-flops."
That is something Obama has sought to exploit in the past. In the run-up to a G8 meeting at Camp David in May, White House officials firmly pressed their European counterparts to rally behind Obama's policy initiatives, according to those involved.
"It was like all of the G8 apart from Russia and Japan were expected to be part of the Obama re-election campaign," the chief of staff of one European leader told Reuters at the time.