Jim Van Etten has stood in the crowd during a trove of presidential speeches.
Kennedy in 1960, Carter in 1980, Clinton a year ago in Lincoln.
The University of Nebraska-Lincoln plant pathology professor heard Obama speak twice at the National Academy of Sciences annual meeting.
But it wasn't until this year — April 22 to be exact — that Van Etten took to the political podium himself.
That day, scientists and others around the world took up their picket signs for the March for Science.
Van Etten, 79, who rallied hundreds of concerned civilians and scientists at Lincoln's satellite march, was never much of an activist, despite living through turbulent political moments in U.S. history.
Like the civil rights movement in the '60s, when scores of activists advocated for an end to racial segregation and discrimination.
Or the surge of anti-war sentiment that swept across the country as the U.S. entangled itself in the quagmire of Vietnam.
“I was never involved in these causes, but I was very supportive,” said Van Etten, who has been teaching at UNL for nearly 50 years. “I was more sympathetic than active.”
But when scientists chose to protest proposed federal budget cuts to scientific research and climate change denial, Van Etten found himself pushed into the frays of activism.
"I think it's odd that I have to march," Van Etten said. "I've been a scientist since 1960 and I certainly don't ever remember scientists having to defend their research to the public."
Van Etten said the current administration has not supported the country's scientific community, with President Donald Trump proposing to cut science funding from the 2018 federal budget and pulling out of the Paris Agreement in June.
Some of the proposed budget cuts, outlined in May, would slash funding to NASA and the Environmental Protection Agency.
In mid-July, the House Appropriations Committee OK'd a bill that would cut $528 million in EPA funding, a more modest cut than Trump proposed.
"There just seems to be an anti-science culture among people in the U.S.," Van Etten said. "That's a huge mistake ... it's been building up, but the attitude of the president questioning climate change has made it worse."
While there are no upcoming scheduled marches, Van Etten plans on being active as long as science and climate change remain issues of contention.
"It's about being in a democracy," he said. "Every citizen has the right to protest and march as long as it's done peacefully ... and I'm a strong proponent of that."