-- Modified on 10/27/2012 8:10:20 AM

In a close election, the president's sophisticated organization -- which Republicans don't seem to have matched -- could make all the difference. I visited Obama and Romney field offices in three swing states -- Ohio, Colorado and Virginia -- dropping in unannounced at random times to see what I could see. There were some consistent, and telling, differences. The Obama offices visited were devoted almost entirely to the President's re election; the Republican offices were devoted almost entirely to local candidates, with little presence for Romney.

Forget the polls, the debates, the last-minute ads and volleys of insults. This is how the Obama campaign plans to win the election.

Four years ago, Barack Obama built the largest grassroots organization in the history of American politics. After the election, he never stopped building, and the current operation, six years in the making, makes 2008 look like "amateur ball," in the words of Obama's national field director Jeremy Bird. Republicans insist they, too, have come a long way in the last four years. But despite the GOP's spin to the contrary, there's little reason to believe Mitt Romney commands anything comparable to Obama's ground operation.

And this time, Obama may actually need it....................