RAPID CITY, S.D. - With the 2018 election in the rear-view mirror, the 2020 election and its potential ballot measures loom on the horizon, including an effort to legalize sports gambling in Deadwood. But it's a safe wager that any legalization of sports betting in South Dakota will have to wait until at least the summer of 2021. In May, the U.S. Supreme Court ruled states could legalize sports betting. Five states have rushed to join Nevada to legalize it. But the South Dakota process, which requires a constitutional amendment, will move more slowly.