There is a political tale that makes the rounds occasionally. It involves a former New Yorker film critic named Pauline Kael, who in 1972 — according to the story — said something to the effect of, 'I can't believe Nixon won. I don't know anybody who voted for him.' "

Conservatives will occasionally have a laugh about it. Look at that liberal bubble around the New Yorker! They don't understand the rest of America!

Well, the paraphrase isn't exactly accurate. Kael actually said this: "I live in a rather special world. I only know one person who voted for Nixon. Where they are I don't know. They're outside my ken. But sometimes when I'm in a theater I can feel them.”

That's not quite so sexy, but it is instructive. And the kind of political siloing that Kael described in her New York social circles has only gotten more pronounced in the decades since, stretching across the country.

Case in point: A new poll from the Pew Research Center. According to the data, just 25 percent of Donald Trump backers say "some" or "a lot" of their close friends support Hillary Clinton. Clinton supporters are even less likely to have Trump-supporting friends; just 19 percent say they have at least "some."

In addition, 31 percent of Trump backers say they have no close friends who back Clinton. And nearly half — 47 percent — of Clinton backers say they have zero close friends who support Trump. Half.

Pew has been at the forefront of detailing Americans' continued polarization and self-sorting — i.e. tending to move to and/or live in places with people who agree with them politically.

As I argued a couple of years ago, this is helping Republicans when it comes to controlling Congress, because Democrats are even more concentrated in overwhelmingly Democratic places — especially in urban areas — while Republican voters are more dispersed and give the GOP an edge in most districts and states nationwide. To perhaps oversimplify it: Fewer Republican votes are gong to waste in urban districts than Democratic votes going to waste in rural areas.

The data suggested that about half of the most conservative Americans said it was important to them to live where people shared their political views, while 63 percent said most of their close friends were politically similar.

Among the most liberal Americans, 35 percent said they wanted to live alongside people with similar views, and 49 percent said most of their close friends did.

The new data from Pew, though, suggest an even-more-siloed 2016 election, in which Trump voters rarely talk to Clinton voters and vice-versa. And even when they do speak to one another, it's perhaps often someone they're not close to and are less likely to empathize with.

And that's especially true with young Clinton voters — 58 percent of whom say they have no close friends who support Trump — blacks (72 percent) and Hispanics (53 percent).

The 2016 election promises to be perhaps the most polarizing we've seen. In fact, the only thing many voters seem to agree on is that they like neither Trump nor Clinton — 25 percent, according to recent polling.

But among the vast majority of Americans who have nonetheless chosen sides, they aren't very likely to have many friends looking to convert them. And that's especially true of Clinton voters.