There are many differences between the 2008 and 2012 presidential campaigns, including the fact there were two nomination fights for an open Oval Office job in 2008 while this year has an incumbent running for re-election. Another difference is the amount of coverage devoted to the two campaigns during the primary season.
From Jan. 1-May 15, 2012, about one quarter (26%) of the newshole was devoted to the presidential contest. That put it well ahead of the No. 2 story, the economy, at 8%. But in the same period four years earlier, the campaign accounted for a full 39% of the newshole, even further ahead of the economy (7%), the No. 2 story at that point in 2008.
Election news got off to big start in 2012, fueled by key Republican contests in Iowa, New Hampshire, South Carolina and Florida. The campaign accounted for 42% of the newshole in January 2012, which is very similar to the coverage in January 2008, when 44% of the newshole was devoted to the presidential race.
Read the full report, This Time Around, Less News from the Campaign Front, on the Pew Research Center's Project for Excellence in Journalism website.