LINCOLN, R.I. (AP) — Legalized sports betting’s rapid spread across the U.S. could face some bigger tests in 2020.

Less than two years after a U.S. Supreme Court ruling opened the door to sportsbooks outside Nevada, sports betting has been legalized in states that are home to about one-third of the nation’s population.

But moral opposition and complicated gambling landscapes might slow the spread elsewhere.

Still, the topic is already on the agendas of lawmakers from Georgia to California.

The most successful efforts so far have come in states that have allowed online betting, a form some states are reluctant to offer.