Political pundits will tell you that historically most debates do not move the needle much when it comes to results in presidential campaigns.

But many of those so-called experts may be rethinking that thesis after Mitt Romney’s vigorous performance last week against a listless President Barack Obama in Denver. Gov. Romney has reset this campaign with less than a month remaining until Election Day.

He rallied his Republican base and made the case for his candidacy to the nation’s undecided voters, and he pulled slightly ahead of the president in the latest poll of likely voters released Wednesday by Reuters.

Romney also took a 1-percentage-point lead in the Real Clear Politics average of the most recent major presidential polls, and on Wednesday moved Pennsylvania, Wisconsin, and New Hampshire from “lean Obama” status to “toss up.”

It has been an unprecedented tightening of a race many in the media were calling all but over just a couple of weeks ago. And it is undeniable that much of Romney’s turnaround can be traced to the 90 minutes he stood on stage beside President Obama.

The performance and its aftermath now bring added pressure to Thursday night’s undercard face-off between Vice President Joe Biden and Republican vice presidential nominee Paul Ryan at Centre College in Danville, Ky.

The stakes are clear: Rep. Ryan can take the gloves from Romney and increase their momentum by throwing additional body blows, or Vice President Biden can slow the Republican’s gains and even reverse them by landing a few punches of his own.

Obama has to wait another week until he can seek redemption in a rematch with Romney. After suffering a first round knockout, having gaffe-prone Biden as your surrogate might not be the president’s first choice.

So far this campaign season Biden has told an audience of African-Americans that Republicans “are going to put y’all back in chains” and admitted to a group in North Carolina that the middle class “has been buried in the last four years.”

Biden has only made a handful of campaign appearances in recent weeks. Instead he has been undergoing debate practice in Delaware with a group of strategists, including David Axelrod, Obama’s top political advisor.

“All debates are tough,” Biden told reporters in Iowa on Oct. 4. “You can sit there and say I would have done that, I would have done this. Well, nothing like standing up before 30, 40, 50, 60, 70 million people.”

Biden managed a mistake-free debate four years ago against then vice presidential nominee Sarah Palin, and it is likely he will turn in another disciplined performance under the spotlight on Thursday night. But Democrats are hoping for a little more than restraint and self-control in the aftermath of a debate performance by Obama that the president himself called “too polite.” Former Michigan Gov. Jennifer Granholm told the Associated Press this week that Biden “is going to play hardball.”

With the stakes even higher in next week’s second presidential debate, a more aggressive Biden will likely be used to field test numerous lines of attacks, which would allow Obama to take, polish, and reuse the more effective ones for his own showdown.

Even Ryan believes that “the vice president’s going to come at me like a cannonball.”

“But the Achilles’ heel he has is President Obama’s record,” Ryan said this week to reporters in St. Petersburg, Fla., “and I’m really looking forward to giving the American people a very clear choice.”

Ryan has his own debate worries. Biden likely will go after congressman’s budget plans and his policies on handling entitlement reform, curtailing government spending, and overhauling the tax code. As the wonkish chairman of the House Budget Committee, Ryan will have to answer Biden’s challenges in ways that don’t overwhelm the viewer with confusing minutia. Ryan had his own debate prep sessions at a resort in Virginia, and it is likely he spent time there trying to prepare for foreign policy questions. While his resume is thin in that area, Biden chaired the Senate Foreign Relations Committee. And there should be questions on foreign policy since the debate moderator, Martha Raddatz, is ABC News’s senior foreign affairs correspondent.

Whatever happens on Thursday it will be refreshing to watch the two men discuss serious issues after a week that has been dominated by a yellow-feathered character in a children’s television program.

Since Romney mentioned Big Bird by name in last week’s debate when he threatened to cut off federal funding for PBS, Democrats have shown an obsessive focus on rallying around the endangered fowl. Team Obama even released a commercial featuring the popular web-footed creature.