Post-election reporting has indicated that the Romney campaign was utterly convinced of imminent victory, notwithstanding the vast number of public polls that showed President Obama with a small but persistent lead.
They had convinced themselves that they knew something that nobody else knew and were stunned to learn everyone else was right and they were wrong. In effect, they came to believe their own spin.
The Obama campaign, on the other hand, was ruthless in letting the numbers tell the story. Having been collecting data on voters for three years, it was rigorous in analysing the race based on facts, not wishful thinking.
As a result, the Obama campaign was able to address real issues when they came up and dedicate resources to where they were most needed. This was particularly effective in mobilising a truly effective ground operation, using the data to 'get out the vote' where it was needed, but also proved useful in responding to new manoeuvres by the opposition. When Romney went to Pennsylvania in the waning days of the campaign, in the comforting belief that the previous wide gap there in favour of Obama was closing, the Obama camp was indifferent. It knew there was no threat. Obama did not match Romney's visits and ended up winning Pennsylvania by six points.
It is a lesson for all comms professionals. Do not get led astray. Challenge your own assumptions. Base decisions on reality. And never let hopes and dreams overcome facts and data.