Tonight, a feisty on-stage showdown as vice president joe biden and his republican challenger paul ryan went head-to-head for the first and only time, with time running short here. The stakes and the... See More
Tonight, a feisty on-stage showdown as vice president joe biden and his republican challenger paul ryan went head-to-head for the first and only time, with time running short here. The stakes and the tension seemed especially high, you a new polls showing a spike in support of mitt rom near after president obama's stumble in last week's debate. So, here's how it all went down tonight. Vice president joe biden and congressman paul ryan. Reporter: From the get-go, this was a sharper, livelier debate. If you do harm to america, we will track you to the gates of hell. What we are watching is the unraveling of the obama foreign policy. Reporter: Joe biden and paul ryan came ready to rumble. Ryan, the intense young gun. Biden, the wily elder statesman who grinned like an old possum as he listened to ryan's attacks. Then came right back at him, biden style. With all due respect, that's a bunch of mularkey. Reporter: It got heated. It got testy. That's a $3,200 benefit cut. That didn't happen. More people signed up. More people signed up for medicare advantage after the change. Nobody is -- mr. Vice president -- Reporter: And what a contrast. Throughout the debate, biden smiled. Smirked. Grinned and cackled. Medicare and social security are going bankrupt. Reporter: Ryan was earnest, intense, super see use. And they grappled all night. On the economy, biden unloaded, attacking mitt romney where president obama had not, on that video tape where romney called 47% of the american people victims who won't take responsibility for their lives. These people are my mom and dad, the people I grew up with. My neighbors. They pay more effective tax than governor romney pays on his federal income tax. Reporter: Ryan got personal. Joe and I are from similar towns. He's from pennsylvania, I'm from wisconsin. You know what the unemployment rate in scranton is today? I sure do. It's 10%. Yeah. You know what it was the day you guys came in? 8.5%. That's how it's going all around america. Reporter: For a vice presidential debate, the stakes were high tonight. After mitt romney's big win in denver and president obama's no-show performance there, biden needed to stop the bleeding. Ryan was going for the jugular, seeking to build the momentum republicans are feeling. The next time you hear them say, don't worry about it, we'll get a few wealthy people to pay their fair share, watch out, middle class. The tax bill is coming to you. Reporter: There was a stark generation gap on that stage toni joe biden, born in 1942, is older than the baby boomers. Paul ryan, born in 1970, is younger than the baby boomers. And ryan looks it. Today, "time" magazine published photos taken last year and on newsstands friday of ryan flexing his impressive guns, a backwards baseball cap and ear buds providing fodder for internet admiration and mockery from right and left. The closest biden came to that was this photoshopped parody of the vice president, courtesy of the onion, watching his supposed car, a firebird. On the campaign trail, ryan's brought an eagerness, a snap and crackle that's energized conservatives. Ryan's displayed some fire in dealing with the intense media pressure of a national campaign. That was kind of strange? Reporter: And biden? Well, biden's been around for a long time. Elected in 1972 at 29, survived the tragedy of losing his wife and baby daughter in a car accident before he took office. We can always get another senator, but they can't get another father. Reporter: And he became a national figure when he scared off against judge robert bork, nominated iffer the supreme court in 1987. Does the majority have the right to tell a couple that they can't use birth control? Reporter: That year, biden launched his first bid for the presidency. Paul ryan was 17 years old. In 1988, the generation gap in a vice presidential debate led to this famous moment. Senator, you'r no jack kennedy. Reporter: Tonight, in a heated exchange about taxes, an echo of that moment. The only way you can find $5 trillion in loopholes, is cut the morning deduction for middle class people. Cut the health care deduction for middle class people. Take away their ability to get a tax break to send their kids to college. That's why they are -- is he wrong about that? He is wrong about that. It's been done before. It has never been done before. A couple of times. Jack kennedy -- oh, now you're jack kennedy. Ronald reagan -- Reporter: At the end, each man summed up and both chose to attack. My friend says that 30% of the american people are takers. Romney points out 47% of the people won't take responsibility. He's talking about my mother and father. Talking about the places I grew up, my neighbors. He's talking about, he's talking about the people that built this country. All they're looking for is an even shot. President obama, he had his chance. He made his choices. This is not what a real recovery looks like. You deserve better. Mitt romney and I want to earn your support. We're offering real reforms for a real recovery for every american. At least it was a lot better watch than the romney/obama. Meanwhile hashtag mularkey is trending nationwide. And martha raddatz has received 80,000 twitter mentions, some saying martha for vice president.
This transcript has been automatically generated and may not be 100% accurate.