- Campaign's defining question is who voters trust to handle economy
- Romney faces same question all challengers do -- is he credible alternative?
- Obama faces challenge of showing how next four years would be different from last four
- Bottom line is the debate rests on which of two men on stage are more persuasive
Denver (CNN) -- To win in November, Mitt Romney must emerge from his first debate with President Barack Obama as the leader on this campaign's defining question: Which candidate do voters trust more to handle the economy?
"He has to paint a compelling picture of a better economic future and why he can lead us there and President Obama can't," GOP pollster Whit Ayres told CNN when asked to define Romney's paramount debate challenge.
Democratic pollster Peter Hart made the same point but in more colorful language: "If Romney loses this issue, then he is toast."
Yes, there are other important challenges for both the Republican challenger and the Democratic incumbent as they share the debate stage for the first of three encounters.
Comebacks, zingers can impact debates Romney, for example, must pass a test all challengers face when appearing side by side with an incumbent: look and sound like a credible alternative, like a president. The GOP standard-bearer also needs to quiet the jitters among Republicans who see the presidential campaign trending in a direction they worry could hurt down-ballot.
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For the president, some aides and advisers worry most about coming across as smug, or too dismissive, of criticism of his economic stewardship.
His burden also includes the challenge of showing how the next four years would be different without helping his challenger's case that the approach of the last four years was misguided.
But given the state of the race, very competitive but with an Obama advantage in several of the most important battleground states, veteran strategists in both parties agree the heavier burden in the first debate is on Romney.
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And they agree his overriding challenge is to seize the upper hand in the economy argument. The candidates enter the Denver debate tied on that key question.
Our new CNN/ORC International poll asked likely voters which candidate would better handle the economy. Obama was the choice of 49%, Romney of 48%.
Pollster Ayres said the key in winning over undecided and persuadable voters is for Romney to make the case the president's economic proposals are "government-driven" and that Romney's rely on small business and the broader private sector as engines of growth.
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The president's response, according to aides familiar with his debate preparations, will be twofold: cast Romney's proposals as little or nothing new, a throwback to favor-the-rich GOP policies that the president argues contributed to the economic ditch, and raise questions about Romney's understanding of, and empathy for, the struggles of working- and middle-class families.
The format should offer voters a clear contrast:
• Three segments on the economy
• One on health care
• One on the role of government
• And one on governing leadership and style.
As always, there is the debate season sideshow known as the expectations game.
It can be fun to watch, especially when high-profile surrogates like New Jersey Gov. Chris Christie ignore the Romney campaign talking points and instead promise a campaign-changing debate performance.
Fun, but in the end meaningless. The surrogates and spinners aren't on the debate stage. Or on the ballot.
This is about Obama and Romney, their first of three debates a test of whether the challenger can make a persuasive case that he has a better economic plan or the incumbent can sell voters on staying the course.
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University of Denver student Sam Garry sits at the moderator's desk before a presidential debate dress rehearsal at the University of Denver on Tuesday, October 2. On Wednesday, President Obama and former Massachusetts Gov. Mitt Romney will face off in the first presidential debate. 
Volunteers sit in for on-air television reporters on Tuesday in preparation for the first presidential debate in the Ritchie Center at the University of Denver. 
Republican presidential candidate Mitt Romney greets a father and his daughter after having lunch Tuesday at a restaurant in Denver. 
President Obama stares at the Hoover Dam in Nevada during a visit Tuesday. 
Mitt Romney boards his campaign plane in Bedford, Massachusetts, on Monday, October 1. Romney is heading to Denver for the first presidential debate on Wednesday. 
President Barack Obama hugs Chasstiry Vazquez after she indroduced him at a campaign event at Desert Pines High School in Las Vegas on Sunday, September 30. 
Obama supporters cheer during Sunday's event in Las Vegas. 
Romney leaves his campaign headquarters in Boston on Sunday. 
A boy reaches out to shake hands with Obama on Sunday in Las Vegas. The president was in Nevada ahead of Wednesday's presidential debate in Denver. 
Romney arrives at the Church of Jesus Christ of Latter-day Saints in Belmont to attend Sunday services. 
Obama talks on the phone with Prime Minister Benjamin Netanyahu of Israel in the Oval Office on Friday, September 28. 
Romney speaks during a rally at Valley Forge Military Academy and College in Pennsylvania on Friday. 
Romney talks to journalists aboard his campaign plane about his phone call with Netanyahu on Friday. 
Cadets listen to Romney speak at a campaign rally Friday at the Valley Forge Military Academy and College in Wayne, Pennsylvania. 
Romney addresses Friday's rally at the Valley Forge Military Academy and College. 
Vice President Joe Biden hugs U.S. Rep. Debbie Wasserman Schultz, chairwoman of the Democratic National Committee, as he arrives for a campaign event Friday in Boca Raton, Florida. 
Romney speaks at a Veterans for Romney campaign event in Springfield, Virginia, on Thursday, September 27. 
Obama supporters cheer at a campaign rally Thursday in Virginia Beach, Virginia. 
Veterans at the American Legion Post 176 pray before Romney speaks Thursday in Springfield. 
People listen to Obama speak at the Farm Bureau Live arena in Virginia Beach on Thursday. 
Obama delivers remarks Thursday in Virginia Beach. 
Supporters cheer as Romney speaks at SeaGate Convention Centre in Toledo, Ohio, on Wednesday, September 26. 
Romney speaks during a roundtable discussion on manufacturing at American Spring Wire in Bedford Heights, Ohio, on Wednesday. 
Supporters wait to see Obama on Wednesday at Toledo Express Airport in Bowling Green, Ohio. Air For One aborted an initial landing attempt in Ohio due to weather conditions. 
Obama addresses supporters at Bowling Green State University on Wednesday. 
Romney delivers remarks during a campaign rally Wednesday at Westerville South High School in Westerville, Ohio. 
Former President Bill Clinton introduces Obama during the Clinton Global Initiative annual meeting in New York on Tuesday, September 25. 
Supporters cheer during a Republican campaign rally Tuesday with Romney and his running mate, Paul Ryan, at Dayton International Airport in Vandalia, Ohio. 
Ryan speaks Tuesday in Vandalia as Sen. Rand Paul, from left, Sen. Rob Portman and Romney listen. 
Former Florida Gov. Jeb Bush hugs a waitress as they wait for Ryan's arrival during a campaign stop at a restaurant in Miami's Little Havana neighborhood on Saturday, September 22. 
Supporters cheer as they listen to Romney speak during a Juntos Con Romney Rally at the Darwin Fuchs Pavilion on Wednesday, September 19, in Miami. 
Romney shakes hands with supporters during the Juntos Con Romney Rally in Miami on Wednesday. 
Obama and David Letterman speak during a break in the taping of the "Late Show with David Letterman" on Tuesday, September 18, at the Ed Sullivan Theater in New York. 
A crew member opens the door to Air Force One after the jet arrived at John F. Kennedy Airport in New York on Tuesday. 
From left to right: Romney, his wife Ann, and son Tagg watch one of Tagg's sons play soccer in Belmont, Massachusetts, on Saturday, September 15. 
Ryan arrives onstage to address the Family Research Council Action Values Voter Summit on Friday, September 14. 
Supporters wait for Romney to speak at a campaign rally at Lake Erie College in Painesville, Ohio, on Friday, September 14. 
Obama arrives at Andrews Air Force Base in Maryland on Thursday, September 13. Obama returned to Washington after a two-day campaign trip with events in Nevada and Colorado. 
Supporters cheer as Romney speaks at a campaign rally in Fairfax, Virginia, on Thursday. 
An Obama supporter attends a rally in Las Vegas on Wednesday, September 12. Obama focused on economic policies during his two days of campaigning in Nevada and Colorado. 
Former President Bill Clinton speaks in support of Obama during a campaign stop in Miami on Tuesday, September 11. 
Obama is lifted up by Scott Van Duzer, owner of Big Apple Pizza and Pasta Italian Restaurant, during a visit to the restaurant in Fort Pierce, Florida, on Sunday, September 9. Obama was on a two-day bus tour across the state. 
President Obama greets supporters during a campaign stop at the Palm Beach County Convention Center in West Palm Beach, Florida, on Sunday. 
Mitt Romney walks through the garage area during a rain delay before the start of the NASCAR Sprint Cup Series Federated Auto Parts 400 at Richmond International Raceway on Saturday, September 8, in Richmond, Virginia. 
Ann Romney, wife of Republican presidential candidate Mitt Romney, waves to the crowd before speaking at a rally in Leesburg, Virginia, on Friday, September 7. 
Supporters try to stay dry in between rain showers while waiting for President Obama to speak at the University of Iowa on Friday. It was Obama's first day of campaigning after accepting the presidential nomination at the Democratic National Convention in Charlotte, North Carolina. 
A girl listens to President Obama speak at the University of Iowa on Friday. 
Vice President Joe Biden, first lady Michelle Obama, President Obama and Biden's wife, Jill, wave after Friday's campaign event at the University of Iowa. 
