According to the poll, 20 percent of registered voters say they have been contacted by the Obama campaign, compared to 13 percent who say they have been contacted by Mitt Romney’s campaign.

That’s on-par with the gap at the same point in the 2008 campaign, when 18 percent of likely voters said they had been contacted by the Obama team and 11 percent who said they had been contacted by Sen. John McCain’s (R-Ariz.) campaign.

But it didn’t use to be the case. The Republicans’ voter turnout machine was once vaunted – particularly its 72-hour voter mobilization program…

Voter contact is one important aspect of a campaign’s ground game, but it is not the whole game. What’s more, Obama’s team has had much more time and money to contact voters nationwide, while Romney’s campaign was focused on individual states during the Republican primary campaign.