The eldest son of Vice President Joe Biden told CNN one reason Republicans are so eager to go after his father is because he is such an effective advocate.

"They reason they would go after him is because he lands punches. He's the single best communicator of the middle class out there. And he is because that's what this campaign is about. How do we, how we do we make sure the middle class continues to have all that it should and move this country forward. The president and my dad want to build this country from the middle class out. Paul Ryan and Mitt Romney want to do it like George W. Bush did. This trickle down, top down mentality," he told CNN Chief Political Analyst Gloria Borger.

Biden sat down with CNN Thursday morning - just hours before he and his family joined the vice president on Air Force Two for the flight to Kentucky for the debate.

Because his home is under renovation, Beau Biden and his family have been staying at his father's Delaware home so he has seen him do some of his studying up close.

After he campaigned in Wisconsin on Wednesday for his father's campaign, he returned to have dinner with his parents.

"We had a nice dinner last night, together as a family," he told Borger. "We had a nice lasagna dinner, and you know, my dad is working hard. But, he's also a dad and a grandfather."

In fact the vice president and his wife, Jill, have babysat Beau Biden's children several recent weekends. And Joe Biden also found time to do some household chores.

"He got up in the morning. We all went to mass. We got the kids off to Sunday school and in between all that I saw him coming out of the laundry room with a pile of laundry. And I'm confident he got that laundry taken care of and then went and cracked his briefing books. He's working really hard," he said.

Beau Biden, who attended some of his father's prep sessions, describes his preparation as "methodical" reading various research books and even looking at a book titled "Young Guns," which Paul Ryan co-authored.

He would not specifically say whether the vice president would go on the offensive, using such attacks as Mitt Romney's comments about the 47% of the country that doesn't pay income taxes but left little doubt.

"You're gonna see Joe Biden. You're gonna see the Joe Biden you've seen on the campaign trail," the younger Biden said. The vice president has been very critical of Romney's comments in campaign stops since the remarks to a closed fund-raiser were leaked to the press weeks ago.

Asked about whether there is a fine line between drawing sharp contrasts and misfiring he said:

"The debate with (Sarah) Palin was instructive on that. There's a lot of talk about the process going into that debate. How do you debate Governor Palin. The dynamic between a man and woman debating," he said.

He then previewed what his father's mission in debates: "He is himself and as respectful to his opponent as he has been in every election for the past 40 years. Be prepared to understand exactly what your opponent is about, who they are. Most importantly, talk directly to the American people who are sitting in their family room."