Republican presidential front-runner Donald TrumpDonald John TrumpRepublicans hold on to Arizona House seat Dems win majority in New York Senate, but won't control it Mulvaney to bankers: Campaign donations will help limit consumer bureau's power MORE said on Sunday that he's not sure how his supporters will respond if he goes into a contested convention with the most delegates but does not get the Republican nomination.

"I don't know what's going to happen," he told ABC's "This Week."

"I will say this: You're going to have a lot of very unhappy people."

Trump had previously predicted riots if he enters the Republican convention with more delegates than any other candidate but is not the party's nominee.

On Sunday, he blamed the large initial GOP field for the complicated delegate math.

"There are so many candidates, so it's very hard to get over that number," he said.

"It's very unfair, in a way."

But he noted he thinks he will get the required number of delegates to secure the nomination ahead of the convention.

"I think I may get over that number fairly easily," he said.

"There's tremendous spirit about make America great again. I mean that's the whole thing."

He said the biggest story in politics is the "huge" amount of people who are coming out to vote for him. People are coming out who have never voted before, he said, adding that the number includes independents and Democrats who are voting Republican.

"I think, frankly, for the Republicans to disenfranchise all those people because if that happens, they're not voting and the Republicans lose. If they — if the Republicans embraced these great people that are showing up, the Republicans are going to have a massive victory. It's not going to be a Mitt Romney slaughter, because he was such a bad candidate," he said.

"The Republicans are going to have a massive victory in November."