At least 18 states stand to loosen their marijuana laws this year.

It looks like 2020 could be a very big year for marijuana legalization.

The year began with a bang when Illinois started recreational marijuana sales, after the state became the 10th in the country and the second in the Midwest to legalize marijuana.

It’s a big deal because Illinois is a big state — the sixth most populous overall and the second most populous to legalize pot — but also because of how Illinois legalized: It’s the first state to allow recreational sales through the legislature, meaning state lawmakers and the governor signed off on it. That typically cautious politicians signed off on legalization is a testament to its growing political appeal.