ANN ARBOR, MI - Organizers of the 47th annual marijuana rally in Ann Arbor are hoping this year's Hash Bash on April 7 will be the last one before cannabis is legalized in Michigan.

They're counting on state voters to approve a ballot proposal in November to legalize recreational marijuana use for people 21 and older, taxing and regulating it much like alcohol.

"For the first 46 years, really the focus has been on state prohibition," said Hash Bash lead organizer Mark Passerini, co-founder of the Om of Medicine marijuana dispensary in downtown Ann Arbor.

"This could very well be the last year we focus on state prohibition and next year we could re-focus toward the ills of federal policy. Federal policy still sees cannabis as a Schedule 1 drug in all forms."

The Hash Bash Planning Committee has announced the lineup of speakers and entertainers for the April 7 rally taking place on the University of Michigan's Central Campus Diag. It's scheduled to last from noon to 4:19 p.m., which is longer than in years past, and it's expected to draw thousands of cannabis users and allies.

"We wanted to give people something to look forward to -- to do on their own -- at 4:20," Passerini said of why the Diag festivities end at 4:19 p.m. "We figure they might be busy at 4:20."

Ann Arbor musician Laith Al-Saadi, who achieved fame as a finalist on NBC's "The Voice," is expected to kick off this year's fest, as he has in the past, by performing the national anthem on guitar.

Politicians, professional athletes and leading marijuana legalization activists from around the country are expected to speak.

"Hash Bash has grown each year since the passage of Michigan's medical cannabis laws. The event has also gained importance as a venue for activists, patients and public figures to speak out against the horrors of cannabis prohibition," committee co-chair Nick Zettell said in a press release announcing this year's lineup.

"With the question of legalization likely on the ballot, this could very well be the last Hash Bash where cannabis is illegal in the state of Michigan," Zettell added. "The qualifications and reputations of this year's speakers are unparalleled by years past and add legitimacy and diversity to the counter-cultural event."

Politicians and candidates on the speakers lineup include gubernatorial candidates Gretchen Whitmer and Abdul El-Sayed, state attorney general candidate Dana Nessel, Ann Arbor City Council members Jack Eaton and Anne Bannister, U.S. Rep. Jared Polis, state Senate candidate Jeff Irwin, and state Rep. Yousef Rabhi. Passerini also plans to read a statement from U.S. Rep. Earl Blumenauer.

Athletes on the lineup include Detroit Lions running back Mike James, former Detroit Red Wings hockey player Darren McCarty, and former NFL player Eugene Monroe.

Passerini said it's significant that James, an active pro athlete, is speaking out. He said James may be putting his career on the line but feels it's important to do so.

Others on the lineup include poet John Sinclair, former Fox 2 News anchor Anqunette Jamison Sarfoh, UM Professor of Pharmaceutical Sciences Gus Rosania, National Cannabis Industry Association board member Khurshid Khoja, and activists Matt Abel, Rick Thompson, Ryan Basore, Sue Sisley, DJ Short, Stephen Goldner, Betty Aldworth, Brandy Zink, Evan Litinas, Jamie Lowell and Nick Zettell.

Local bands Ma Baker, Honey Monsoon and Cosmic Knot are scheduled to perform starting at 2 p.m. The full schedule can be found on the Hash Bash mobile app.

While it's not unusual for many people to light up a joint at Hash Bash, UM warns that it's not an amnesty day where campus police look the other way on pot smoking on campus.

While the university allows the rally to happen as a matter of free speech, campus police follow state law and will arrest people caught with drugs, including marijuana, on university property. Elsewhere in Ann Arbor, pot has been decriminalized since the 1970s, with the city penalty for possession being a $25 ticket for a first offense.

This year's Hash Bash once again coincides with the annual Monroe Street Fair, which features live music and vendors.

A Hash Bash after party also is taking place at the Blind Pig, featuring Laith Al-Saadi and the Macpodz.

Passerini said more and more people are coming to Hash Bash from all over the place, including Michigan, Ohio, Indiana, Illinois and Wisconsin, so the festivities on the Diag have expanded to accommodate the crowd size. In addition to the Diag and Monroe Street, he said there may be a third venue added next year, possibly Ingalls Mall where the Ann Arbor Summer Fest is held.

Several marijuana policy organizations are involved with this year's Hash Bash, including Students for Sensible Drug Policy at UM, Green Wolverine at UM's Ross School of Business, MILegalize, Michigan NORML, Student Advocates for the Medical and Responsible use of Cannabis, and the Coalition to Regulate Marijuana like Alcohol.

The Coalition to Regulate Marijuana like Alcohol turned in roughly 365,000 signatures to the state last fall in hopes of getting its legalization proposal on the November 2018 ballot.

The proposal is still waiting for signature review by the state Bureau of Elections, but its supporters are confident it will meet the 252,523-signature requirement to go on the ballot.

Irwin, a former state rep from Ann Arbor, has been a strong supporter of the campaign and was a paid member of its staff for a while.

"I feel strongly we have sufficient signatures," he said. "We reviewed our signatures before turning them in."

Irwin said marijuana prohibition has been a failure of government just like alcohol prohibition was a failure.

He argues regulating it in a legal environment gives more control over it than "keeping it underground."

"Almost nobody thinks prohibition is working," he said, arguing pot is less harmful than alcohol from a public health perspective.

A group called Healthy and Productive Michigan is opposing the legalization proposal, arguing there are economic, safety and health concerns that come with recreational marijuana use.

"We are committed to keeping Michigan's economy thriving and our citizens healthy, by preventing the legalization of recreational marijuana in Michigan," the group states on its website, arguing any tax revenue from legal marijuana is outweighed by the societal costs "just like tobacco and alcohol, where costs far outweigh revenues."

About 57 percent of Michigan voters support marijuana legalization, according to a recent poll of 600 likely voters conducted by the Glengariff Group, The Detroit News reported last month.

The Hash Bash committee is hosting two free panel discussions at UM on Sunday, April 8, the day after the political rally.

The first is from 2-3:10 p.m. at the Michigan League and is titled "Athletes and Cannabis." Panelists include Mike James, Eugene Monroe and Darren McCarty.

The second is from 3:15-4:19 p.m. at the Michigan League and is titled "Medicine and Cannabis." Panelists include cannabis researcher Sue Sisley, UM Professor of Pharmaceutical Sciences Gus Rosania, and Evan Litinas, chief medical officer at the Om of Medicine marijuana dispensary in downtown Ann Arbor.