DENVER - Minnesota's drug laws have torn the Botker family in half.

Seven-year-old Greta Botker suffers from a rare, aggressive form of epilepsy. Seizures wracked her body a dozen or more times a day, and nothing — not drug regimens, not special diets, not even brain surgery — helped for long.

Then the Botkers heard that in Colorado, where marijuana is sold legally, a cannabis strain known as Charlotte's Web appeared to dramatically decrease seizure rates in children like Greta.

So Maria Botker took a wrenching step last fall. She packed a moving van, took Greta and left the family farm in Clinton, Minn., bound for a new life without her husband and two other daughters, to enroll Greta in Colorado's medical marijuana program.

"We just decided that there was nothing more important than giving Greta a shot" at a better life, said Maria Botker, a 38-year-old nurse.

It's a choice that has thrust the family into a roaring national debate that is about to erupt in Minnesota — one that is dividing legislators, health professionals and law enforcement in a way few policies ever do.

As the momentum to legalize marijuana builds, 20 states have taken the step in some form. Six more are considering it this year, including Minnesota. Even Wisconsin, which has some of the toughest marijuana possession laws in the region, has a medical marijuana bill in its State Assembly this year.

Polls now show more than half of Americans favor some level of legalization. But even as public attitudes shift, some worry that wider access to marijuana could harm more people than it helps.

The intensifying debate has become a battle of anecdotes: The son scoring drugs to ease his mother's nausea during chemotherapy vs. the father who finds out that medical marijuana from other states is circulating on his kids' college campus. The family smuggling a joint to Grandpa in hospice vs. the therapist rushing to the emergency room, where a teenager is getting his stomach pumped after mixing too much marijuana with too much alcohol.

Every law enforcement association in Minnesota opposes legalization. Gov. Mark Dayton has said he won't sign off as long as the police are opposed. When President Obama, who has admitted to smoking pot in his youth, said recently that marijuana was no more dangerous than alcohol, Dayton, a recovering alcoholic, shot back: "Alcohol is plenty dangerous. … Why would we want to add another drug to the equation?"

Family time, Botker style

While the Minnesota Legislature gears up for the legalization debate, the Botkers live divided lives. Mark works the family farm and cares for daughters Emma, 13, and Lora, 10.

Meanwhile, 800 miles away in a house just outside Denver, Maria adjusts to her new reality. She telecommutes to her old job and every day gives Greta a prescribed capsule of cannabis extract mixed with olive oil. Greta's seizures are waning, from 15 a day to as few as four, and she has been weaned off three of her five other prescriptions.

Nightly, the five Botkers gather around their iPads for family time, Maria and Greta on one side, Mark, Emma and Lora on the other. It's a ritual unlikely to change unless Minnesota law does.

Greta points delightedly at the screen when she sees her father and big sisters, Maria Botker said, and peeks behind the iPad, trying to find them and pull them closer. "It's the best part of our day, and it's the worst part of our day, when it's over," Maria Botker said. "My heart just breaks. … I want my family back together."

Long lines, many choices

Colorado is adjusting to its own new normal.

More than 10,000 customers stormed the 136 shops that opened on Jan. 1, the first day of legal sales. Once inside, they could pick from brands with names like Cannalope Haze ("melon taste"), Island Sweet Skunk and White Widow. Within a week, retailers racked up sales of $5 million. Soon, many had sold out of anything edible or smokable.

Lines at pot dispensaries are long, prices are astronomical and shopkeepers have the giddy air of home-brew enthusiasts opening their first microbrewery. Readers of the Denver Post can check out bong reviews, the "Strain of the Day" and even get recipes for a "marijuana-enhanced" sour cream coffee cake.

Demand like that is what worries Minnesota law enforcement. While many are sympathetic to families with suffering loved ones, they say that medical marijuana is a system easy to abuse and tough to regulate.

They noted in a position paper to the state that of the 108,000 people in Colorado seeking medical marijuana in 2012, more than 90 percent of prescriptions were to treat nonspecific conditions like "pain relief."

Their staunch opposition has kept marijuana classified in the same category as drugs like heroin and LSD. Every year about 9,000 people are arrested in Minnesota for sale or possession of marijuana, making up more than half of all narcotics arrests in the state. In 2004, the state decriminalized small amounts of marijuana, with anything under 1.5 ounces considered a petty misdemeanor. However, amounts over that remain a felony offense, carrying up to five years in prison and a $10,000 fine. A push to legalize medical marijuana passed the Minnesota House and Senate in 2009, but was stopped by Republican Gov. Tim Pawlenty, who vetoed the bill with law enforcement's support.

"This is a situation where both proponents and opponents have strong arguments on their respective sides," Dayton said. "I don't think it's a matter of negating one set of concerns or the other. It's trying to strike a balance and decide what's in the overall public interest."

Dayton said he's aware of the bill that will come before the Legislature this session, but he said passage is doubtful unless common ground is forged between the two sides — something he said is unlikely in a short session.

The bill, sponsored by Rep. Carly Melin, DFL-Hibbing, and Sen. Scott Dibble, DFL-Minneapolis, would legalize medical marijuana for a broad range of conditions, with doctors' approval. Patients could possess up to 2.5 ounces of marijuana. An ounce of marijuana can yield as many as 50 joints. Patients could grow as many as a dozen marijuana plants of their own or buy the product from a licensed dispensary — one per county, or more in large urban areas like the Twin Cities.

The state would use application and licensing fees to help offset the estimated $250,000 needed to monitor and regulate medical marijuana in the first year.

Michigan, which legalized medical marijuana in 2008, spent $4 million to administer its program last year but collected more than $10 million in fees from the more than 130,000 people who applied.

Melin says she is unfazed by opponents and is being inundated by calls and letters from families who desperately want access to the drug for their sick and dying loved ones.

An obligation to help

"Even if every single cop in the state was opposed to it … when I'm sick, I go to the doctor. I don't go to the police department," Melin said.

Not every cop is opposed to legalization. One of Melin's co-sponsors is state Rep. Dan Schoen, DFL-St. Paul Park, a police officer who has worked in narcotics enforcement.

"There's far more abuse — and life-altering abuse — with prescription drugs than there is with marijuana in any way, shape or form," said Schoen, who has watched friends and relatives go through agonizing chemotherapy treatments that made it hard to say no when other families approached him about legalization.

"When you see people suffer, and they don't need to, I think there's an obligation when you're a public servant, whether you're a police officer or [a lawmaker to say] 'How can I help?' "

Schoen said he is confident the legislation has enough safeguards to keep medical marijuana out of the wrong hands, and he hopes the law enforcement groups will meet with lawmakers to discuss ways to improve the bill.

Younger users pose a problem

But the prospect of doctors writing prescriptions for marijuana troubles Dr. Carrie Borchardt, a Minnesota child and adolescent psychiatrist who spends her days working with teens whose lives have been derailed by drug addiction.

"Substance use in young people is a much scarier thing than it is in adults," said Borchardt, who is president of the Minnesota Psychiatric Society, which opposes medicalizing marijuana.

The adolescent brain, she said, is still maturing, still forming connections that will regulate decisionmaking and executive functions. Substance abuse during those formative years, Borchardt said, can wreak havoc on young brains that adult users may never experience — memory impairment, lower IQs, even a higher risk for developing schizophrenia. According to the National Institute on Drug Abuse, about 9 percent of regular users become addicted, a figure that rises with use.

"Even if we aren't prescribing [marijuana] for the teenagers, it will make it more accessible," Borchardt said. "And it gives the impression that it's safe."

An industry blooms

In Denver's Medicine Man marijuana dispensary, Elan Nelson walks through a series of indoor greenhouses. Bright green plants crowd every square inch, each tagged with a microchip traceable by police driving near the building, which sits amid a bland suburban office park. Overhead cameras pan the room, monitored by building security and the state regulators who track every seedling, every bud and every cutting, down to the last gram.

Customers in the lobby show their driver's licenses to security at the door, then stand in lines that snake around the room, waiting to consult with staff "budtenders" about the properties of the strains on display.

"If you were to smoke a sativa, you'd still get some housework done," Nelson said, gesturing to a tray of young plants stretching toward the grow lights. "You could vacuum, clean the windows. You'd still be able to function. With an indica, you'd be mellowed out on the couch for a few hours." Customers pay about $50 an eighth of an ounce, depending on the strain they choose, plus 36 percent tax. Medical patients pay about half that, with an 8 percent tax.

'This stuff will get out'

Colorado's embrace of legal pot didn't happen overnight. Voters opted to legalize medical marijuana in 2000. In 2012, they voted to amend the state Constitution so that anyone older than 21 could buy, possess or grow pot for recreational use.

Opponents say that is the path they fear: Sanctioned medical marijuana that builds demand and mainstream acceptance of recreational use and ends in full-scale legalization.

Even if Minnesota limited legalization to medicinal purposes only, said John Kingrey, executive director of the Minnesota County Attorneys Association, "This stuff will get out." Kingrey noted that medical marijuana from other states has found its way to his kids' college campus in Fargo. "It will end up … in our neighborhoods."

Denver attorney Brian Vicente, a driving force behind Colorado legalization, acknowledged that the state's "robust and successful" medical marijuana experience helped grow public support. "We were really able to convey to citizens of our state that marijuana is a product, like any other," he said.

Jennifer Brooks • 651-925-5049