"I think he has to be more Wisconsin than wonk, he can be both," Gingrich told CNN on Sunday, adding that Ryan comes across as "somebody who really understands the Midwest."

Another dynamic to watch for Thursday could be the two candidates' shared religious values. For the first time in U.S. history, both tickets include a Catholic. While both Ryan and Biden proudly talk about their background on the campaign trail, observers note that the nearly 30-year age gap between the two will perhaps be a more visible element on the stage Thursday.

Earlier on NBC's "Meet the Press," Gingrich said he anticipates Ryan to acknowledge the "generational difference" with his opponent.

"I suspect he is going to be respectful of Biden," the former speaker said. "There is a generational difference here that I think will lead Ryan to not give an inch, but to not be very hostile."

A recent CNN/ORC International poll found that 55% of likely voters thought Ryan will fare better in the debate, while 39% said Biden will win.

The two have stepped up their attacks against each other on the campaign trail in recent weeks. Biden has taken aim at Ryan's budget plan, saying it could hit seniors with more taxes to their Social Security benefits. In Ohio last week, Ryan hit back, saying Obama and Biden were the real threats to health and retirement programs

"In fact, Joe Biden himself voted to raise taxes on Social Security benefits, and as a senator, President Obama voted to keep those tax increases in place three times," Ryan said at a campaign event, defending his plan that would offer a subsidized version of Social Security.