ROBERT SIEGEL, HOST:
Now a survey that confirms how much our political parties have become polarized and how recently. The Pew Research Center has been polling Americans about values since 1987. This year's survey marks 25 years of asking us about government, religion, the environment. And here's the news. Americans, taken as one big sample, haven't changed all that much. But the values of Republicans and Democrats have changed. Twenty-five years ago, people who identified with the two parties answered some questions about immigration and the environment, for example, pretty much the same way.
Today, those same questions might as well be litmus tests for party affiliation. Andrew Kohut is the president of the Pew Center, and he joins us once again. Hi, Andy.
ANDREW KOHUT: Happy to be here.
SIEGEL: And what's happened here?
KOHUT: What's happened is that we have much broader differences by party affiliation than by any of the things that typically describe public opinion. The income gaps, the education gaps, the religious gaps, they're all the same as they were 25 years ago, not the gaps by party affiliation. The percentage difference between Republicans and Democrats is twice as great as it was. The interesting thing about this rise in polarization is that over the past 25 years almost all of the jump in differences between Republicans and Democrats occurred within the last two administrations, starting with the middle of President Bush's first term. And in the Obama years we saw a steady upward spiral in Republicans and Democrats differing on not everything but let's say just about everything.
SIEGEL: Give us an example of an issue that the answers weren't that different between Democrats and Republicans in '87 and now they're very different.
KOHUT: Well, let's take the environment. Back in 1987, 93 percent of Democrats and 86 percent of Republicans said there needs to be stricter laws and regulations to protect the environment. Today, 93 percent of Democrats still feel that way but only 47 percent of Republicans agree.
SIEGEL: There's a question you ask about is it government's responsibility to maintain a social safety net for the poor. Again, back in 1987, I gather the gap wasn't that huge between Democrats and Republicans.
KOHUT: No. There was a slight Democratic advantage on that opinion, but the percentage of Republicans has fallen by 20 percentage points who believe that the government has a responsibility to take care of people who can't take of themselves.
SIEGEL: Of course Democrats hearing that may say I knew it. The Republicans have veered right in the past few years, and they've abandoned these consensus positions that used to be held by roughly similar numbers of people in both parties.
KOHUT: Well, that's not true because the Democrats have become more liberal. They are certainly more secular. More of them say they doubt the existence of God than did 25 years ago. The percentage of Democrats today versus then who say they support efforts to improve the positions of minorities even if it means preferential treatment is up 19 percentage points. So the Democrats have changed in their own way as well.
SIEGEL: One reading of this is that each party has gone through a process of purification in recent years, moderates and liberals leaving the Republican side, and conservatives and some moderates leaving the Democratic side, making them more ideological parties.
KOHUT: Well, they are certainly smaller than they once were. We have a record number of people who think of themselves as political independents - 38 percent. That's a 75-year high. So the parties are smaller. More members of the parties think of themselves in ideological terms. The percentage of Republicans who think of themselves as conservatives have gone up to 68 percent, from 60 percent in 2000, and there are more liberal Democrats than there were.
SIEGEL: The survey by the Pew Research Center is called Trends in American Values: 1987-2012, Partisan Polarization Searches in Bush, Obama Years. Andy Kohut, president of the Pew Research Center. Thanks for talking with us.
KOHUT: You're welcome, Robert.