When a politician is in trouble, he usually falls back on what he knows best -- the world he saw around him when he entered into political awareness as a young adult.

That's what seems to have happened to the Democratic ticket after Barack Obama's disastrous performance in the Denver debate Oct. 3.

So Obama on the campaign trail and Joe Biden in the vice presidential debate fell back on what they know from their formative political years.

At least that's the best explanation I can come up with for the Obama campaign's obsession with Big Bird.

On the campaign trail in the week after the presidential debate, Obama mentioned Big Bird 13 times -- 13 times more than he mentioned Libya.

And the Obama campaign rolled out a 30-second spot showing Mitt Romney saying "Big Bird" several times. Even liberals labeled it the worst TV ad they had ever seen.

But someone in the Obama campaign -- and remember that the campaign always reflects the candidate -- thought hitting Romney for defunding PBS, "Sesame Street" and Big Bird would be devastating.

Never mind that "Sesame Street" gets little money from the government and has an endowment in the hundreds of millions. As the "Sesame" folks assured us, Big Bird is going to continue to be on the air whatever Romney does.

The Big Bird offensive would have been more effective in the late 1970s and early 1980s, when Obama came of political age. Lots of people then saw public broadcasting as a needed alternative to commercial television.

Better your kids watch "Sesame Street" than cartoons interlaced with ads for sugared cereals. And they'd learn to respect ghetto kids in the process.

It's an argument with some appeal still in the state Senate district Obama sculpted for himself in 2002, linking black neighborhoods on Chicago's South Side with the rich liberals in Gold Coast apartments. But for ordinary voters, with 133 cable channels to choose from, "Sesame Street" and PBS are just not a big deal.

Fast forward to Joe Biden at the debate. He clearly did what the Obama campaign wanted: lots of lusty attacks on Mitt Romney, repeated mentions of that magic number 47 percent, smirks and groans and derisive laughter.

He interrupted Paul Ryan and moderator Martha Raddatz more than 80 times, which may have been offputting to Independents and Undecideds. But he gave core Democrats like interrupter Chris Matthews something to cheer about.

On substance he was weaker. He denied that the White House knew that Ambassador Christopher Stevens was attacked by terrorists rather than in a spontaneous demonstration prompted by an anti-Islam video. That's in vivid contrast with sworn testimony Wednesday that the State Department knew it was a terrorist attack all along.

Biden's statement was either an untruth or a confession of incompetence. If the State Department had the information, why didn't the White House?

Another telling moment came when Raddatz asked Biden what Obama would do about the budget deficit other than raise taxes on high earners. Raise taxes on high earners, Biden repeated again and again. That's the second-term agenda.

On entitlements, Biden said that Social Security and Medicare were "guaranteed." That's not what most young voters think. They understand in some visceral way that the current programs are unsustainable.

In his closing statement Biden identified Romney's "47 percent of the people who won't take responsibility" with "my mother and father. He's talking about the places I grew up in, my neighbors in Scranton, [Pa.], and Claymont, [Del.]"

Those people, born around 1920, would rally to candidates who promised to maintain Social Security and Medicare when Biden first ran for the Senate in 1972. They would understand his reference to Republican opposition to these programs when they were enacted in 1935 and 1965. But that's 77 and 47 years ago now.

But the Obama campaign wrote off the white working class last spring. Biden was making an appeal that worked in his political youth but not so much these days.

Polling suggests Obama lost ground with women, and the CNN instant poll showed Biden scoring badly with them. As for young people, will they be attracted to a man who keeps shouting "Malarkey!" a word not in common use for years?

In the two debates, voters saw a near-comatose Obama and a near-manic Biden -- and two sober, well-informed Republicans. That's not a good contrast for Democrats.

Michael Barone, The Examiner's senior political analyst, can be contacted at mbarone@washingtonexaminer.com. His column appears Wednesday and Sunday, and his stories and blog posts appear on washingtonexaminer.com.