With 6% reporting, Trump leads by 70.6% to Cruz's 11.4% and Kasich's 11%.
Following Trump’s sweeping victory in Indiana last Tuesday, rival Cruz delivered his resignation speech, only one week after declaring Carly Fiorina as his running mate. Having been mathematically eliminated months ago, Kasich followed suit the next day.
As the presumptive nominee, Trump has shifted his focus to the general election, going after likely Democratic nominee Hillary Clinton.
Republicans are also holding a primary race in Nebraska, with polls closing at 9.
Earlier on Tuesday, Cruz indicated that he would reenter the race if he were to win Nebraska, since his name is still on the ballot. This outcome, however, is extremely unlikely.
The next Republican primary will be held in Oregon next Tuesday.