Organizers of this year's Hemp fest at Myrtle Edwards Park had to answer criticism that their event is too hippie to be taken seriously as a political rally.
McPeak and his hairstyle are responding to a culture shift at Hempfest, in its 18th year in Seattle.
At the first Hempfest in 1991, 500 protesters gathered at Volunteer Park to push a fringe political agenda.
But this year, scheduled speakers include Seattle City Councilmember Nick Licata and state Rep. Roger Goodman, D-Kirkland.
As the event which is expected draw some 100,000 people to Myrtle Edwards Park, Elliott Bay Park and the Olympic Sculpture Park this weekend enters the mainstream, there is controversy: Is it time for the pro-pot movement to shed its countercultural, hippie image?
Among the tie-dyed drifters stereotypically associated with marijuana rallies are tourists, older couples, students, families and mainstream folks who share the belief that marijuana should be legal.
McPeak considers the event's diversity one of its strengths.
But Dominic Holden, Hempfest's former director, thinks tie-dye and prayer flags on the stages undermine the event's credibility.
Two months ago, the Hempfest board voted to ban Holden from speaking at Hempfest. Holden, who writes for The Stranger newspaper, wrote in March that the event is a "patchouli-stained ghetto."
"It plays into a stigma that hippies want to legalize marijuana primarily so they can have more access to their own vice," he said in an interview.
"We do more and more every year to make our event more professional ... but toning down the event and the countercultural vibe here is not something I feel pressured to do."
Besides, McPeak says, his event is successful, and so are his political causes.