When Tony Sertich graduated from Chisholm High in 1994, he was one of about 80 seniors who crowded the stage, he recalls.

This year, the Iron Range Resources and Rehabilitation Board commissioner and former House DFL majority leader returned to his alma mater as the commencement speaker. The graduating class numbered fewer than 40.

Reports like that have become commonplace on the Iron Range. At community gatherings in Eveleth, Virginia, Gilbert or Biwabik, turnout is lighter than it was 20 or 30 years ago because communities are smaller than they used to be. St. Louis County's population is down more than 22,000 since 1982, state demographer Susan Brower reports, with the bulk of that decline occurring on the Iron Range.

Consequently, turnout will be lighter than it used to be at Iron Range polling places on Tuesday, DFL primary election day.

That reality likely matters most in the near term to the prospects of DFL congressional contender Jeff Anderson.

A former Duluth City Council member, Anderson, 35, has made much of his Iron Range roots in his campaign against former U.S. Rep. Rick Nolan and former state Sen. Tarryl Clark for the DFL rights to take on Chip Cravaack, the Eighth Congressional District's rookie Republican representative, in the Nov. 6 general election.

A fourth-generation Iron Ranger, born and raised in Ely, the son of a Minntac miner -- these features of Anderson's pedigree have been driven home relentlessly in recent weeks. So have been his endorsements by Iron Range political luminaries Tom Rukavina, Gary Cerkvenik, Jerry Janezich, Ron Dicklich -- and Sertich, a fellow whom many DFLers still wish had entered this race himself.

"He's a friend," Sertich said to explain his preference for Anderson over Nolan and Clark. "Friends come before politics for me."

Time was when Iron Range roots and relationships came before most other things in determining the region's votes. Minnesota might have elected a Gov. Warren Spannaus in place of Iron Ranger Rudy Perpich in 1982 had it been otherwise.

It was also a given that Rangers vote in DFL primaries in numbers akin to general election turnouts in some less politically passionate, pro-DFL parts of the state.

Dedication to DFL primaries still prevails in northeastern Minnesota, says Don Bye, longtime chair of the Eighth District DFL Party.

But, Bye said, "the demographics of this district have changed dramatically. The remaining folks who hang on to the idea that the Eighth is the Range and Duluth are as mixed up as those who think the Range and Duluth are one and the same. They're not recognizing the gradual growth and shift of the population to the southern part of the district."

The district's southern growth numbers are eye-popping. Since 1982, the population in Crow Wing and Pine counties is up 50 percent; Isanti, 60 percent; Chisago, a whopping 108 percent.

Sertich noted another kind of demographic change with political implications. Not only are there fewer Rangers than 30 years ago, but today's mineworkers think and vote differently. He elucidated: "The last great hire by the mines was in the 1970s. Those folks are retiring now at a significant clip. They're being replaced by people who don't have as strong an attachment to the DFL and to unions. It's because a lot of the battles that used to attach people to unions here have already been fought."

Union loyalty used to be the glue that sealed Range voters to the DFL. That glue appears to have weakened.

Those are the changes that are cracking the DFL's rock ribs in the Eighth. Chisholm native DFL Rep. Jim Oberstar lost his seat in 2010 after 18 terms not so much because his Range neighbors abandoned him, but because there weren't enough of them to counter the Republican wave that swept the rest of the district.

Some DFL loyalists want to believe that Cravaack's defeat of Oberstar was a one-off, isolated episode related to Oberstar's neglect of his home base and a GOP national wave. They expect the district to revert to DFL dependability this year, regardless of who wins the three-way primary contest Tuesday.

That would be the thinking of people who turn a blind eye toward the empty seats at Range graduations and gatherings. Demographically savvy DFL primary voters are thinking differently.

______________________

Lori Sturdevant is a Star Tribune editorial writer and columnist.