Throughout the campaign, much was made of the tremendous ground organization that Obama had built. Yet, according to the exit polls, Obama's organization did not contact a higher percentage of voters than Kerry's did in 2004. In both 2004 and 2008, voters were asked "Did anyone call you or talk to you in person on behalf of either major presidential campaign about coming out to vote?" In 2008, 13% said that the Obama campaign had contacted them while 13% reported that both campaigns had done so. That means that 26% of voters nationwide had been contacted by the Obama campaign. This figure is the same as Kerry's contact rate among 2004 voters. In fact, nationally, the major difference between 2004 and 2008 was that the Republican contact rate dropped. In 2004, 24% of voters reported that they were contacted by the Bush campaign but in 2008, just 19% were contacted by McCain.
Of course, national figures may mask more significant patterns at the state-level. I was able to get statewide results for the question on campaign contact in 17 states. These results are plotted in the chart below for every state where the data were available. Nearly all of these were states that Obama ultimately won; the only exceptions are West Virginia and Missouri.
Every state except West Virginia falls above the diagonal line, indicating that the Obama campaign contacted more voters than McCain in 16 of these 17 states. However, the margin of Obama's advantage in campaign contact did vary. In several states, Obama held an advantage similar to that captured by the national contact margin (7%). However, Obama had at least a 12% advantage in the percentage of voters contacted in Iowa, Virginia, Indiana, Colorado, and Nevada. Of course, Iowa and Nevada were states where the Obama campaign had spent significant time and effort organizing for the January caucus events; this effort appeared to pay off in the general election as 50% of Nevada voters and 42% of those in Iowa reported having been contacted by the Obama campaign. Virginia and Indiana were states where Obama invested heavily during the primary and general election campaign. 50% of Virginia voters and 37% of Indiana voters reported contact from the Obama campaign. Finally, the Democratic convention was held in Colorado, which may have helped make that the state where Obama contacted more voters than anywhere else--51% of Coloradans reported being contacted by the Obama campaign.
With the exception of New Mexico, reported contact rates are available for each of the states that Obama flipped from red to blue in 2008. The chart below compares Obama's advantage in contacting voters in each of the states he flipped with his national advantage on this measure.
Note that of the three states that come closest to Obama's national advantage, two are states that have been targeted by both parties in recent presidential elections. Thus, it may be the case that Republicans already had the infrastructure to be more competitive with Obama's ground game in traditional battleground states like Florida and Ohio, but they were unable to catch up with the organization Obama built in new newer battleground states.
Finally, it is difficult to trace the precise impact of this ground game effort relative to other factors during the campaign. But for fun, the chart below plots the Obama contact advantage in each of the 17 states against the change in the Democratic margin in that state from 2004 to 2008.
Again, we shouldn't draw too many conclusions from this plot, but it does appear that Obama tended to improve more on Kerry's 2004 electoral performance in states where he held a larger advantage in voter contact.
Ultimately, the state-level data provide important context about Obama's ground game advantage. Obama dominated the ground game in most of the states he turned from red to blue in 2008, particularly the newer battleground states like Nevada, Colorado, and Indiana. This organizational advantage was undoubtedly one of the major factors behind such a large vote swing in those states.