Business was brisk at Jack Nelson-Pallmeyer's U.S. Senate campaign office in Uptown, though it was a weekday midafternoon. Earnest volunteers worked clusters of phones and computers. The front desk directed a steady flow of calls and walk-in traffic.

Maybe, thought I, activity was high because two days earlier, Nelson-Pallmeyer's rival for DFL endorsement, Al Franken, revealed that he'd made a little tax error in the past five years. He owed at least 17 states at least $70,000, he said, and New York and Minnesota owed him a tax refund.

But the hubbub wasn't new, vouched campaign spokesperson Chris McNellis. The two dozen kids, moms, students, seniors and computer guys buzzing around 3027 Holmes Av. S. were a typical complement. "Our campaign has been consistently growing, especially in the last six weeks," she said.

Nelson-Pallmeyer may be the guy mentioned at the bottom of stories about Franken as "also running" for the DFL endorsement to take on Republican Sen. Norm Coleman on Nov. 4. But it should be reported that the University of St. Thomas assistant professor of peace and justice is "also running hard," in the company of a devoted and well-organized band of supporters.

Whether the band is growing numerically at a rate sufficient to make him a serious contender for DFL endorsement won't be known until the party's state convention casts its first ballot on June 7. The Nelson-Pallmeyer campaign won't share its delegate count. (The convention, both Franken and Nelson-Pallmeyer say, will settle their contest. Both promise no primary challenge if the other is endorsed.)

But whatever momentum Nelson-Pallmeyer had a week ago is bound to have been spurred by the tax questions that dogged Franken last week.

It's not that Nelson-Pallmeyer is speaking out about his rival's troubles. Far from it. He refuses to comment about Franken, or even say much by way of contrasting himself with the former "Saturday Night Live" entertainer.

Nelson-Pallmeyer sticks religiously to describing his reasons for backing a single-payer health-care system, an immediate withdrawal of American troops from Iraq, and a full-bore strategy for cutting the nation's consumption of oil.

"Religiously" is a word that suits this campaign. Nelson-Pallmeyer doesn't trumpet his faith. But his story is a reminder that Christian faith can motivate political action on the left as well as the right. A Lutheran, he holds a master of divinity degree from Union Theological Seminary. Much of his career as a writer, educator and anti-poverty activist has been connected to the church.

This is his second bid for elective office. The first ended at the Fifth District DFL convention in May 2006, where he was among the top finishers in an 11-person race, but lost the party's congressional endorsement to U.S. Rep. Keith Ellison. That showing surprised the old pols who had handicapped the chances of an unknown professor at slim and none.

Old pols have been wrong about a professor's chances before, this campaign likes to observe. Two photos of Paul Wellstone hang prominently on the campaign office wall, in silent testimony to that earlier professor's success. It's likely no coincidence that Nelson-Pallmeyer's campaign signs are an evocative green and white.

The latter-day professor-politician lacks Wellstone's oratorical firepower, but not his hopeful spirit or passion for grassroots politics.

There's another parallel, too. Nelson-Pallmeyer also often hears something Wellstone heard in 1990: "You're too liberal" to be elected.

But the candidate claims he's hearing less of that lately -- and not just since Franken's campaign hit a speed bump. Rather, he says, it's because "people are in real financial pain right now. I don't have to tell people that our country is unraveling. They're telling me how they are experiencing our country unraveling in their lives. They see my campaign as the one that is addressing those issues pretty directly."

History suggests that there may be something to what he says. Hard times have occasioned a left turn in state politics before. The Nelson-Pallmeyer campaign may be trying to conjure Wellstone's ghost. But my guess is that the spirit of Floyd B. Olson is hovering nearby, too.

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