This year, perhaps no state illustrates the changed dynamics better than Pennsylvania.
The state offers 20 Electoral College votes and has been competitive up until Election Day in every presidential campaign for the past few decades even though it's voted Democratic in every race from 1992 on.
Republican groups tried to make the state competitive for Romney this year by running ads early on.
But, one month out, Romney isn't aggressively competing in the state, a fact that pains its Republicans.
GOP Gov. Tom Corbett was still lobbying last week, arguing that Romney's support for relaxed restrictions on coal production made him more competitive in the state than polls suggest. That hope hung over a door in a Harrisburg campaign office in the form of a sign: "Pennsylvania believes."
"We've just got to do the work on the ground," state Republican campaign spokesman Billy Pitman said, standing beneath that hopeful sign. "There's still time."
But Romney has only nominally campaigned in Pennsylvania for the general election, as he struggles to narrow Obama's advantage with white working-class voters and women. Despite Romney having 24 campaign offices in the state, registered Democrats outnumber Republicans by roughly 1 million and Obama leads solidly in polls. The president has spent a relatively light $5 million on advertising, early on in the campaign.
Then there is Michigan, Romney's native state, which has voted Democratic in every presidential election beginning in 1992. GOP groups tried to lay the groundwork for Romney to compete, running ads earlier this year. But Romney aides decided against trying to put it in play, acknowledging that it would be difficult for him to win given his initial opposition to the automotive industry bailout.
On the other side, Obama's team hasn't put its money or time where its mouth has been in Arizona, Georgia or Texas.
Four years ago, Obama received 45 percent of the vote in McCain's home state of Arizona without spending any time or money. This year, aides said early on that an influx of Hispanic voters made it an attractive place to compete. Obama aides say it's still possible the president could air ads in Arizona before Election Day.
Aides also spoke early on about possibly competing in Texas, yet nothing ever came of that. And Democrats had been eyeing Georgia, arguing that it — like Southern states North Carolina and Virginia — was prime for a Democratic return to power, given an influx of young and racially diverse voters.
Yet, all those states are among the 41 that aren't seeing the action, at least for now.
Associated Press writers Kevin Freking and Don Rehill contributed from Washington.