Presidential candidates win when they adapt. And that is exactly what Mitt Romney and President Obama are each trying to do.
The debate last Wednesday, events in the Middle East and the better-than expected jobs numbers on Friday are forcing the two campaigns to adjust to a new reality in the final month before Election Day. Neither can simply follow their playbook and expect to succeed.
Now, the question is which of them will recognize the changes and put in place a new approach? That campaign will improve its chances to win the White House.
Here is a look at how the dynamics have shifted, and how the candidates are reacting in the week ahead.
UNEMPLOYMENT: For more than a year, Mitt Romney's most consistent economic argument was a simple one: Unemployment had stubbornly remained above 8 percent for almost Mr. Obama's entire presidency. That is a firing offense, Mr. Romney said again and again.
"We've had 43 straight months with unemployment above 8 percent," Mr. Romney said in his closing statement at Wednesday's debate.
Now, though, Mr. Romney will have to adjust his stump speech and his ads. The drop in unemployment to 7.8 percent robs Mr. Romney of the simple argument he has been making, and will require a new line of attack.
Mr. Romney's initial attempt to tweak his message was to question the statistic. Speaking at event in Virginia on Friday, he said that people who "just drop out altogether" from the work force had artificially lowered the rate.
But that technical explanation isn't a rallying cry. So by Friday's rally, Mr. Romney had seized on a slightly different jobs message that does not dwell so much on the current unemployment rate. The new approach will be on display in rallies throughout the coming week.
"There were fewer new jobs created this month than last month," Mr. Romney said in Abingdon, Va. "We don't have to stay on the path we've been on. We can do better."
A WEAK DEBATE: For Mr. Obama, the new reality was created moments after the conclusion of the debate on Wednesday night. His lackluster performance pierced his confidence, slowed his momentum and raised questions about his strategy.
For Mr. Obama's campaign, the question is how to adapt. Senior strategists on Thursday hinted strongly that Mr. Obama will be much more aggressive in his next debate -- an approach the president has already begun taking at rallies in the last several days.
Campaign advisers say Vice President Biden will reinforce that approach in his debate with Representative Paul D. Ryan on Thursday. And the campaign's allies have already begun calling Mr. Romney a serial liar -- an approach that will continue in ads this week.
A new video released by Mr. Obama's campaign on Sunday is an example of the new approach. Called "Cameras," the video argues that Mr. Romney's debate performance was a series of lies that distorted his record.
But the biggest challenge for Mr. Obama's campaign may be how to respond if polls this week show his campaign has lost the momentum it seemed to have at the end of September.
LIBYA AND THE MIDEAST: Both campaigns have long argued that the economy is the biggest issue of the campaign. But the killing of the American ambassador to Libya -- and the broader instability in the Middle East -- has changed that dynamic a bit.
Mr. Romney appears ready to adjust his message by seizing on the Libya situation to question the president's judgment and leadership. He plans a foreign policy speech on Monday at the Virginia Military Institute in Lexington, Va.
The Republican candidate clearly hopes to put Mr. Obama on the defensive surrounding the attacks on the diplomatic compound in Libya. The question is whether he can turn that argument into a broader indictment of the president's foreign policy.
For Mr. Obama, the overseas events also present the need to adapt. His campaign will need to find answers for the current situation in Libya and the Middle East while more aggressively making the broader case for his leadership abroad.nation
This article originally appeared in The New York Times.