To start with, Mike Pence is currently the governor of Indiana. Indiana has some of the strictest marijuana laws in the country, and Mike Pence doesn't want that to change. In the state, you can get six months in prison for possessing any amount of marijuana. You can get a felony and up to 2 1/2 years in prison for possessing just over an ounce.
Lawmakers in Indiana have attempted to reduce the punishments for low-level marijuana crimes, but Mike Pence has lobbied against these efforts.
"I think we need to focus on reducing crime, not reducing penalties," Pence said in 2013. "I think this legislation, as it moves forward, should still seek to continue to send a way strong message to the people of Indiana and particularly to those who would come into our state to deal drugs, that we are tough and we're going to stay tough on narcotics in this state."
Furthermore, just this year, Mike Pence signed legislation that reinstates mandatory minimum sentences for drug dealers. This would appear to be in response to Indiana's serious methamphetamine problem that has grown drastically during his time as governor. As many have said before, mandatory minimums do essentially nothing to curb crime and add to the country's mass incarceration problem. (Many have said Pence is in bed with the private prison industry.)
Indiana has also faced an HIV epidemic under Mike Pence, which some say could have been avoided if he hadn't initially opposed needle exchange programs in the state when an epidemic looked possible. Pence seemed to think helping addicts get clean needles wasn't a good idea until the reason you do that, stopping HIV from spreading, became too real of a problem.
The most ironic and hilarious thing about Mike Pence is he actually has signed one law that was good for marijuana users, but he had no idea he was doing it. In 2015, Pence signed the Religious Freedom Restoration Act, which lets businesses cite religion in a legal defense. It also lets them discriminate against LGBTQ people if it's for religious reasons.
What Pence didn't know is that a man named Bill Levin would use the law to establish the First Church of Cannabis. Members of the church worship, well, cannabis. I'm sure he didn't see that coming.
Finally, Pence has a -20 rating with NORML, partially because he'll vote for any War on Drugs legislation he sees. He's supported the military patrolling the Mexican border to stop drugs from coming in and voted for more money to fight drug cartels. This qualifies him as having a "hard on drugs" stance, according to the organization.
Donald Trump appears to be planning to let his VP handle "domestic and foreign policy," basically everything, while he focuses on "making America great again." Whatever that means. If Mike Pence ends up handling the whole country's drug policy, things could go terribly wrong.