Even a demography geek like me knows better than to claim that a few numbers explain all of the shifts to the left and right that have been seen lately in Minnesota politics. But I've come across some median age stats that I think say a lot.

Consider: Minnesota's statewide median age in 2015 was 37.9 years. That's close to the national average of 37.8. It ranks this state's population as younger than, say, Florida (41.8) and older than Texas (34.4).

But the statewide median masks big internal differences, wider than any state demographer Susan Brower says she's seen since median age data became available in 1980. In 21 of Minnesota's 87 counties — mostly in the western third of the state — the median age has surpassed 45 years. In four counties — Aitkin, Cook, Lake and Lake of the Woods — it's above 50.

But in St. Paul, it's 31.4. In Minneapolis, it's 31.9. It's younger still in St. Cloud and Mankato, both home to large state universities.

Those are politically consequential differences. To be sure, other big socioeconomic disparities between greater and metro Minnesotans pop out of U.S. census data, too. There are growing gaps to behold in income, educational attainment and racial population composition within this state.

But think about the likely political preferences of a population dominated by 20- and 30-somethings vs. one loaded with seniors, and you'll have a lot to ponder.

A former state demographer and pollster for this newspaper, Hazel Reinhardt, told me years ago that the events that occur when a voter is between the ages of 18 and 24 often determine his or her political bent for a lifetime. University of Minnesota political scientist Larry Jacobs said last week he subscribes to the same idea. He joined me in speculating about the political thinking of Minnesotans who witnessed the Vietnam War and Watergate during young adulthood vs. those who came of age during the Great Recession.

"Just think about the differences in formative experiences, community life experiences, expectations. It's almost literally black and white," Jacobs said.

Well, yes: Attitudes about race and immigration are among the differences one might expect. Native-born Minnesotans who remember the 1950s knew a state whose population was almost all white. The share of Minnesotans circa 1960 whose ancestors weren't all from Europe was 1.2 percent. In the 2010 census, it was 16.8 percent, and that trend line is forecast to keep climbing.

Among some in Minnesota's older set, mix good-old-days nostalgia with a steady diet of immigrant-bashing on conservative talk radio, and you've got a recipe for a Trump voter.

Attitudes about government are also likely to vary by age. As documentarians Ken Burns and Lynn Novick recently reminded PBS watchers, the baby boomer generation saw good reasons to mistrust government. Generation X, the cohort that followed the boomers, were susceptible to buying President Ronald Reagan's argument in the 1980s that "government is the problem," and that there's a great potential for wealth in America if only government would get out of the way.

But the boomers' kids don't wince at the very mention of Vietnam, and they have no memory of Reagan. They're more likely to get riled when someone mentions the high cost of higher education.

"The Great Recession had a big impact on how younger people see the role of government," Jacobs said. "If you came of out of college during the Great Recession with a lot of debt and had a hard time getting a job, you're likely to support a lot more government help for getting an education and getting a job."

The result: A 70-something U.S. senator from Vermont became a hero among the millennial set in 2016 by calling for free college, universal health care, a $15-an-hour minimum wage and more concerted antipoverty efforts from the federal government. Bernie Sanders scored a win at Minnesota's DFL precinct caucuses with an appeal that was stronger among the young than the old.

The Sanders campaign of 2016 in Minnesota has morphed into the Our Revolution campaign of 2017 in Minneapolis and St. Paul city elections. As Jacobs described on these pages last summer, Our Revolution is an "ultraprogressive" force that threatens to divide the state DFL — just when the party needs all the unity it can muster to hang on to the governorship in 2018.

Our Revolution is a quick upstart. It has endorsed candidates for 12 of the 13 Minneapolis City Council seats and seven of the nine seats on the Park and Recreation Board. In six council wards, Our Revolution candidates are challenging sitting DFL incumbents; in only one of those six was the incumbent able to hang on to DFL endorsement. In St. Paul, where only the mayor and school board are on the ballot, Our Revolution's backing of Dai Thao helped block an endorsement at the city's DFL convention.

The under-32 median age in Minneapolis and St. Paul helps explain the impatience Our Revolution is exhibiting, and maybe a good deal more. Its campaign is waged heavily on social media, where attacks on other DFLers flow freely. A city DFL "elder" — someone in her 50s — called that "very much a generational thing. Younger people see social media as a place for expressing opinions and emotions. It's a place to scream. They don't much care whether there's a real person on the other side."

Generational misunderstanding may be hardening as a result, she said. "Older people are saying, 'What the hell?!" and younger people are shrugging, 'What's the problem?' "

The real test for a youth-fueled political movement isn't whether it can stir up the status quo during a campaign. It's whether it can get its adherents to the polls. That's what the Nov. 7 election will prove.

"The rap on younger voters is that they make a lot of noise but then get distracted and don't vote," Jacobs said. It's easier to mobilize older people who have long been in the habit of voting.

The low median ages in Minneapolis and St. Paul suggest this: The higher the turnout in the two big-city elections, the greater the chances that Our Revolution will pass its test and install its candidates in office next January.

Lori Sturdevant is a Star Tribune editorial writer. She is at lsturdevant@startribune.com.