RAY SUAREZ: Finally tonight, we turn to politics and a look at the impact of the youth vote in this year's presidential election. In 2008, young people went to the polls in record numbers, with 66 percent of 18-to-29-year-olds supporting President Obama, helping to sweep him to victory.
But, this year, the president's support among that age group dipped to 60 percent, although young voters proved much more critical to his re-election win.
That's the subject of a new analysis by the Pew Research Center. And we are joined now by Michael Dimock, one of the study's lead authors.
And, Michael, there were confident predictions before Election Day that youth was simply not engaged, not enthusiastic, and not going to show up on Election Day.
What really happened?
MICHAEL DIMOCK, Pew Research Center: Well, they did. And I think it was probably the biggest surprise to a lot of analysts looking at those exit polls on election night.
The youth vote was as strong in terms of turnout as it was four years ago, and a lot of pre-election indicators suggested there might be more of a falloff. So Obama's support slipped a bit among that group, but their numbers and the heavy tilt continued in his direction was really decisive.
RAY SUAREZ: So, with a shrinking electorate, since many fewer voters turned out this time, if you hold, that means you have increased your impact, no?
MICHAEL DIMOCK: In a way. I think they were about the same share of voters this year as they were four years ago, which is important, because there was a sense in '08 that that was a unique moment, where young people frustrated with the Bush administration were coming out in numbers for a youthful presidential candidate.
Four years later, after four long, hard years of a tough economy that has arguably hit this group, this generation harder than anybody else in terms of finding good jobs, to keep that enthusiasm and to maintain those turnout numbers is really striking.
RAY SUAREZ: Now, we mentioned already that the raw number came down for President Obama, but he still won by a sizable margin.
But, inside that 60 percent, what changed since '08? For instance, white voters tailed off, didn't they?
MICHAEL DIMOCK: That's right.
I mean, Obama won the support of white voters -- young white voters four years ago. That group, 18-to-29-year-old white voters, tilted the other direction this year. They favored Romney by a somewhat slim margin.
But they don't make up that big of a share of the young voters. What kept Obama in such strong standing is the fact that this age group is so diverse.
RAY SUAREZ: So, when people talk about the changing face of America, you see it more in the 18-to-29s than you do in any of the other age cohorts?
MICHAEL DIMOCK: Right. Absolutely.
This generation, 42 percent of voters in 18-29 were non-white, 58 percent were white. That is far different than the folks 30 and older. Only 24 percent of them were non-white.
Those non-white voters continue to back Democrats very strongly, as they have in previous elections. And they make up an enormous part of this age group. And that was a big factor for Obama.
RAY SUAREZ: So, in your analysis, are there states where this vote clearly made the difference?
MICHAEL DIMOCK: Well, in a close state, almost any vote can make a difference, but there's no question that keeping that youth vote was critical to Obama.
In four states, Ohio, Florida, Virginia, and Pennsylvania, Obama lost by a slim margin among the voters 30 and older. He wouldn't have carried those states but for the strong support, 60 percent or more, among younger voters in those states.
And I think, even more importantly, he had the turnout among young voters, and he didn't even lose in the margin in some of those key states. In Virginia, Ohio, and Florida, he won by the same margin among young people that he did four years ago.
So, while slipping a bit nationwide, he kept the energy and kept the support among young voters where it counted.
RAY SUAREZ: When we try to slice and dice the electorate, is there really a youth vote? Because every youth is something else? They come from their region, they come from their state. They're well-educated or not-so-well. They're high-income or low-income. They come from different racial and ethnic groups.
Is a youth voter more like another youth voter than they are like other Catholics, other Southerners?
MICHAEL DIMOCK: Right. No, it's true.
This is a diverse generation, as any generation is. Baby boomers were characterized as something, while they're very diverse.
All the generations have differences, but this generation really has a character that showed up early on, even before Obama came into the scene and energized people.
In the 2004 election, this was an engaged electorate that was already showing its Democratic leanings. And that's not just about personalities. It's about substance. They have somewhat different values about what they prioritize and what they think the government should be doing.
This is the one age group that wants the government to do more, whereas all the older age groups want the government to get out of their hair. This is the one generation that backs the health care reform and is much more liberal, not surprisingly, on some social issues like gay marriage or immigration.
Those fundamentals are part of the character of this generation. There's hardly uniform agreement within the generation, but it is a characteristic that really sets this age group apart.
RAY SUAREZ: So what does the party affiliation look like right now?
MICHAEL DIMOCK: Well, it's much more Democratic.
This is a generation that has leaned Democratic all along. And they continue to do so.
In fact, their margin -- the Democratic margin didn't slip at all between 2008 and 2012. And that was a big question mark coming into this election. Could the Democrats hold their partisan advantage in this key group? And they seem to have done so.
I think a part of that is that the image of the Republican Party is very weak in this age group right now. The Republicans haven't done a lot to appeal to this age group and that's one of the challenges they face moving forward.
RAY SUAREZ: Michael Dimock of Pew, thank you very much.
MICHAEL DIMOCK: Thank you.
RAY SUAREZ: And you can still help us grade the 2012 election. We partnered with the Pew Research Center to create a voter satisfaction quiz. Fill it out. Share it with your friends. That's on our home page.