A recent Fox News poll shows a late-summer surge for anti-establishment candidates on both sides of the aisle.

Former neurosurgeon Ben Carson made significant gains since the first GOP primary debate, finishing with a net gain of eight points (bested only by Carly Fiorina’s 12 point gain) in the Fox poll. During the same time, Democratic contender and self-identified socialist Bernie Sanders closed some of the gap on frontrunner Hillary Clinton, moving up to 30 percent.

In an interview with Fox News Sunday’s Chris Wallace, Carson gave the far-left side of the political spectrum a shoutout as he defended his 10 percent flat-rate tax plan, which is based on the biblical practice of tithing.

"You make $10 billion, you pay $1 billion. Now, I know a lot of people say that’s a problem because that guy’s still got $9 billion left, we need to take his money. But you see Chris, that’s called socialism," Carson said Aug. 16. "And I recognize a lot of people here who believe in socialism. That number is increasing."

We were curious about Carson’s claim that socialism is gaining ground in America. We found that the polling evidence is lacking, but experts said there is a noticeable shift particularly younger Americans.

We contacted Carson's campaign but did not hear back.

What Carson misses

There’s simply very little data on on the topic, said Karlyn Bowman, who studies public opinion at the conservative American Enterprise Institute. And given how infrequently the questions about socialism are asked, she cautioned against extrapolating any trends from existing polls.

Charles Franklin, a professor of public policy and law at Marquette University, searched the University of Connecticut’s Roper Center archive on public opinion and got 70 hits for "socialism" out of more than 500,000 questions dating back to the 1930s.

The issue pops up from time to time — for example, during the 1960s and President Barack Obama’s first bid for the White House — but there’s no long-running debate over the ideology.

"We haven’t had a serious socialist movement or competitive party in the country, so the issue hasn’t been a constant focus of public opinion," Franklin said.

Here’s a sampling of what some historical polls show:

It’s important to note that all these questions ask different things — and none asks whether someone "believes" in socialism, as Carson said. Also, the questions come from different research centers that have different margins of error and use different polling methodologies.

Given all the caveats, we’ll take the experts’ advice and refrain from connecting the disparate dots.

What Carson gets right

However, Carson does have a point that attitudes towards socialism have changed. Recent polling suggests that socialism is viewed more favorably, particularly among younger generations, though overall the numbers are still low.

A Pew Center poll conducted during the Occupy Wall Street protests shows the number of people who had a positive reaction to the word "socialism" rose from 29 percent in 2010 to 31 percent in 2011. Similarly, 13 percent said they viewed a socialist in the presidential race positively in May 2015, according to a survey by Rasmussen Reports, up from 8 percent in the 2008 cycle.

Both polls report margins of error around 3 percentage points, so the numbers may not actually be statistically significant.

Numerous polls point to a generational shift, says Joseph Schwartz, a political theorist at Temple University. Compared to older Americans, people from 18 to 34 have more favorable attitudes towards socialism. Add in a working class and/or minority background, the attitude becomes much more favorable.

"Folks under 45 did not come of political age during the Cold War," Schwartz explained. "Millennials, I think, vaguely associate socialism more with Nordic social democracy than with authoritarian Communism, so they see these countries as less unequal than more ‘neoliberal’ U.S.-style capitalism."

Beyond the polls, Schwartz pointed to the surge of Sanders, the Occupy Wall Street movement and Black Lives Matter as indicative of "the revolt of the baristas" — mostly white, college-educated younger adults who’ve grown wary of capitalism, high college debt, weakened unions, corporate tax cuts and bailouts.

Overall, the country is leaning left, and liberalism has seen great momentum in social issues like gay marriage and marijuana legalization, according to Bowman of the American Enterprise Institute.

In other words, to millennials and Gen-Xers, supporting socialism is more about Scandinavian-style living than Soviet governing structure.

"Does that mean that millennials are for social/worker/state ownership of the means of production? Probably only a small minority," Schwartz said.

Our ruling

Carson said the number of people who "believe in socialism ... is increasing."

There has been sparse polling over the years about what the public thinks of socialism, so experts told us to be cautious about the numbers that do exist.

However, there are suggestions in the polling data that younger Americans are more open to the idea of socialism, which they equate with European social programs and Nordic-style social democracies.

We rate his claim Half True.