Both New Jersey Gov. Chris Christie and Sen. John McCain said they expect Romney to shine when he shares the Denver stage for the first time with President Barack Obama.

“We have a candidate who is going to do extraordinarily well on Wednesday night,” Chris Christie said on “Face the Nation” on CBS. The Republican governor said Romney will have his first chance to directly contrast his vision for the country with that of Obama.

“This whole race is going to be turned upside down come Thursday morning,” Christie said.

McCain — who has debated both Obama and Romney — also predicted Romney will fare well this week. He said the debate will likely have more viewers than any other presidential showdown in history and argued that both candidates will “do excellent in their own way.”

“This will be a very large audience. He wants to speak directly to the families, the people on their couches at home, having snacks, drinking a beer, drinking a soda, whatever it is, and tuning in for the first time. And that’s who he’s speaking directly to,” she said.”I think you could argue that Mitt has had a lot more recent experience, obviously,” McCain said on CNN’s “State of the Union.”

As the 2008 Republican presidential nominee, McCain battled Romney during the GOP primaries, then competed against Obama during the general election debates. While he foresees a record audience Wednesday night, McCain doesn’t anticipate any major “breakthrough” moments from the debates, saying those have become far and few between in the last couple of decades.

“I can’t remember the last time there was one of these comments that grabbed everybody’s attention because, frankly, the candidates are too well prepared. They’re well-scripted,” the longtime senator said.

Obama, meanwhile, flew to Nevada on Sunday, where he’ll hold a rally before digging in for a few days of preparation ahead of Wednesday’s debate in Denver. Sen. John Kerry of Massachusetts, who’s playing the role of Romney in the president’s debate practice, will join Obama this week in Nevada.

The president’s campaign spokeswoman, Jen Psaki, told reporters on Air Force One that Obama likely won’t be flinging barbs during this week’s presidential debate.

“If you’re expecting that, that’s probably not what he’s going to deliver,” Psaki said.” He’s speaking directly to the American people and what they want to hear is what his plan is for moving the country forward.”

Psaki was referring to reports that Romney was “working on zingers” and memorizing short attack lines to fire off at the president on Wednesday, the first presidential debate this cycle.

Psaki added the president’s focus will be more trained on the audience at home than his competitor on stage.

Political experts agree much is at stake in the first debate. Obama leads most national polls and has a significant advantage in polls in several key battleground states where the race is expected to be decided.

A number of political analysts have said that Romney’s best chance of getting some momentum for his campaign will come in the debates, which stretch over most of October and leave two weeks of campaigning before Election Day.

The first debate will set the stage for the final weeks of the race, said Republican strategist and CNN contributor Alex Castellanos.

“This is their first chance — our first chance to see the two gladiators in the arena alone, so how they — who is the Alpha dog in this debate? That’s what we want to see. Because if you can’t beat the other guy, how can you lead the country?” Castellanos said on “State of the Union.”

Furthermore, Castellanos said Romney will face pressure to show a likability factor on the debate stage but said his best bet is to “show us what he would do as president the next four years,” something Castellanos argues Obama has yet to clarify.

“Romney, his canvas has a little bit of blank space there. He could do that,” he said. “But clearly, this debate is one of those rare political events where both candidates are the underdogs.”

Meanwhile, on the expectations front, both campaigns continued Sunday to set the bar low, a game the teams have been playing for well over a week.

Romney’s running mate, Rep. Paul Ryan, for example described Obama as a “very gifted speaker.”

“The man’s been on the national stage for many years, he’s an experienced debater, he’s done these kinds of debates before,” Ryan said in an interview that aired Sunday on Fox News. “This is Mitt’s first time on this kind of a stage.”

Meanwhile, Obama’s team points to the more than 20 debates in which Romney took part during the Republican presidential primary this cycle.

“He’s prepared more than any candidate I think maybe in history, certainly in recent memory,” Obama political adviser David Plouffe said Sunday on ABC’s “This Week,” adding he believes Romney will “probably have a good night on Wednesday night.”

Team Obama, also noted Sunday that Romney tends to have better timing during debates than the president

“(Romney) has been disciplined and been able to give short answers, so we know that’s a strength,” Psaki told reporters on Air Force One, adding the Obama on the other hand has “tendency to give longer substantive answers.”

She continued to set the bar high for Romney, saying the Republican nominee and “his team have been clear, what they need, what they expect from the debates is a game-changing performance.”

As for the vice presidential debate, scheduled for October 11, Ryan on Sunday built up his competitor. While Vice President Joe Biden has made several notable gaffes as vice president, Ryan said his opponent was “disciplined” and will leave that trait off the debate stage when they face off in Danville, Kentucky.

“Joe is very good on the attack. Joe is very good at trying to confuse the issues so that the person leaves the debate confused about who stands for what,” Ryan said. “My job is to make sure that they’re not confused about what we stand for and what they stand for.”

While Obama is in Nevada, the Romney campaign told CNN that Sen. Rob Portman of Ohio, who’s playing the role of Obama in Romney’s debate preparations, will travel with the former Massachusetts governor on Monday to Colorado. Romney will hold a rally in Colorado that night before final debate preparations.

A CNN/ORC International poll just after the Democratic National Convention earlier this month asked likely voters which candidate is more likely to win the debates. The poll results give Obama a 25-point (59%-34%) advantage over Romney.