Election Day is less than two weeks away, and President Obama and Mitt Romney, in the midst of whirlwind tours across a handful of battleground states, are trying to sway a dwindling group of undecided voters. With the race promising a nail-biting finish, the two candidates are also counting on strong turnouts from their respective bases. To accomplish both these tasks, the campaigns will rely heavily on their get-out-the-vote operations, which have already begun work in early-voting states. The Obama campaign claims to have the most extensive ground game in election history, giving it an edge over Team Romney. How good is Obama's ground game? "Forget the polls, the debates, the last-minute ads, and volleys of insults," says Molly Ball at The Atlantic, "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 Romney commands anything comparable to Obama's ground operation...

In a technical sense, the Romney campaign actually does not have a ground game at all. It has handed over that responsibility to the Republican National Committee, which leads a coordinated effort intended to boost candidates from the top of the ticket on down...

The disadvantage of this is that the RNC is composed of its state Republican Parties, which vary dramatically in quality. States like Florida and Virginia have strong Republican operations, while those in Iowa and Nevada haven't recovered from attempted takeovers by Ron Paul partisans, and the Ohio GOP still bears the scars of a protracted leadership fight earlier in the year.

The get-out-the-vote push is particularly critical in a swing state like Iowa, which began voting weeks ago, says Kyle Leighton at Talking Points Memo.

Political watchers say President Obama has been successful this year at getting his supporters to take advantage of Iowa's early voting system and that likely has given him a head start at a time when he still leads in the polls…

[A] key for the Obama campaign will be to overwhelm the Republican ticket before Nov. 6 so that Election Day becomes somewhat of a foregone conclusion.

And consider Colorado, where the race is neck-and-neck, say Nicholas Riccardi and Kristen Wyatt of The Associated Press:

Denver-based GOP operative Katy Atkinson said that in a state as close as Colorado, the ground game may make all the difference.

"The Democrats have spent a lot of money registering new voters, and those can be the toughest to turn out. So they have the tougher job, but they also have a very sophisticated program," Atkinson said. "If anybody can do it, the Obama people can. But that's the whole question in Colorado."

Nowhere does it matter more than in Ohio, a near-must-win state for both candidates that Obama is currently leading by a slim margin. The Obama campaign "is waging the most intensive ground operation in U.S. electoral history in Ohio," says Ed Pilkington at Britain's The Guardian:

It has blanketed the state with 125 field offices and is sending out an army of volunteers, backed by the latest digital technology, to hunt down the 3 percent of voters who have yet to make up their minds…

The Obama canvassing operation in Bowling Green, as in other key constituencies across the country, is powered by a sophisticated set of digital tools developed for this election cycle called Dashboard. This takes the Democratic party's database, Vote Builder, which contains personal data on millions of individuals, and connects it to volunteers knocking on doors…

But don't forget, the GOP has improved its ground game since 2008 as well, says Grace Wyler at Business Insider:

While the Romney campaign organization does not approach the scale of the Obama network, the Republican National Committee has built up its ground organization since 2008, as evidenced by the 2010 midterm elections and, to a lesser extent, the Wisconsin recall races of 2011 and 2012. 

In addition, outside conservative groups, like the Tea Party-affiliated Freedomworks and Americans For Prosperity, have made significant strides in voter mobilization since 2009, as have social conservative groups like Ralph Reed's Faith and Freedom Coalition.