Kansas City, Mo. ? A song penned by Michael Brewer and Tom Shipley in a Kansas City coffee house 35 years ago landed the folk-rock duo on President Richard Nixon’s so-called “enemies list” and prompted Vice President Spiro T. Agnew to label them subversives of American youths.

Still, “One Toke Over the Line” became a hit in 1970 for Brewer and Shipley and gained broad airplay on radio stations nationwide.

Songs like that — ones that either challenge or defy authority — don’t stand much of a chance of gaining similar broadcast exposure these days, Brewer says.

And songs that protest the war in Iraq or criticize George Bush are even less likely to get radio play.

“We live in a far, far more conservative time than we did in the ’60s and early ’70s,” Brewer said. “The pendulum swings, and it’s swinging way to the right now.”

The dearth of popular protest music may stem from the lack of a military draft and changes in the music industry during the past three decades, said Ken Zambello, an instructor at Berklee School of Music in Boston.

“In the ’60s, small labels put out that stuff and it probably had a better chance of getting airplay,” Zambello said. “I don’t know how many minor labels even get close to getting airtime now.

“One of the biggest things I remember from growing up was the draft,” he said. “The lack of that takes a certain steam out of situations.”

Michael Budds, a music history teacher at the University of Missouri School of Music, said all wars were different in terms of the music they spawn.

“The big music war was the Civil War,” he said. “Hundreds of thousands of songs were generated by the Civil War because the subject was overwhelming to the people who experienced it.”

The Vietnam War generated similar emotions because American youths were being forced into the war by the draft. With no such impetus for protest, Budds said, the Iraq war doesn’t seem to be such a hot topic on university campuses.

“Every conversation I’ve had about the war in Iraq at the University of Missouri with a student was initiated by me,” he said. “The war in Iraq is not of immediate concern to the students I teach.”

And because popular music is “commercial and pragmatic,” he said, there would be more protest music if consumers demanded it. But they’re not.

“At the time during the Vietnam War, people looked to musicians and actors as social leaders and wanted their point of view,” Budds said. “They had a leadership role that I don’t think they have in our culture right now.”

“Country” Joe McDonald, whose “I-Feel-Like-I’m-Fixin’-to-Die Rag” became one of the most popular anti-war anthems in the late ’60s, said protest music historically doesn’t get much radio play.

“Real protest music is in your face, in the establishment’s face,” McDonald said from his home in Berkley, Calif. “It’s disquieting, unnerving, makes you nervous. Particularly in the status quo, because it speaks the truth.”

Two of his newest protest songs, “Cakewalk to Baghdad” and “Support the Troops,” can be found on his Web site, and McDonald acknowledges neither likely will make it beyond the Internet.

When Natalie Maines of the Dixie Chicks told a London audience before the war began that she was ashamed to share her home state of Texas with Bush, radio stations across the United States boycotted the group’s music, and some organized rallies at which Dixie Chicks tapes and CDs were trashed.

But once Americans become less tolerant of losing their young men and women, he said, protest music will have its best chance to re-emerge on the popular music scene.

“When the number of American dead gets up around 3,000, people are going to come unglued,” he said. “And if Bush opens up another front, I don’t know what’s going to happen.”

So far, just over 1,500 American soldiers have been killed in Iraq, compared to more than 58,000 who lost their lives in Vietnam between 1964 and 1973.