Some have compared 2012 to 2004. At The New Republic, William Galston writes:
The basic structure of the 2004 campaign differed fundamentally from the one we’re now enduring. The available evidence suggests that even in the short-term, the attacks on Romney have been measurably less successful than were those on Kerry. And Obama’s supporters seem to have forgotten that the reason Bush prevailed was because enough Americans ended up approving of his record and leadership in the areas they cared about the most.Michael Barone suggests two other differences between 2004 and 2012:
One is that the 2004 election occurred during a period of unusual stability in American voting behavior.
In the preceding four congressional elections, Republicans won between 48 and 51 percent of the popular vote for the House and Democrats won between 46 and 49 percent. In 2004 the parties' percentages in both the presidential and congressional popular vote were within the same narrow ranges.
Since then voting behavior has been much more volatile.
There's another difference between 2004 and 2012 that is salient. In 2004 George W. Bush's Republican base was pretty much united on issues. Foreign policy realists and neocons were all on board.
Cultural conservatives supported the Bush tax cuts. Few economic conservatives had much problem with Bush's stands on abortion or embryonic stem cell research.
Barack Obama's Democratic base is more heterogeneous. ...
Blocking the Keystone XL oil pipeline from Canada pleased gentry liberals who embrace every green cause. But private sector labor unions don't like it a bit.
Bashing Romney's record at Bain and Company may be helping him with some modest-income voters. But it risks antagonizing the affluent, which is a problem for a candidate who last time ran even, 49 to 49 percent, among those with incomes over $100,000.