"Every week - boom, boom, boom, I knocked them off," Trump told his supporters in California referring to the defeat of other Republican candidates by him.
From 17, only three are left in the fray.
"She (Hillary) will go down easier than any of the people we just beat. You are going to have an unbelievably good result in November," 69-year-old Trump said.
He needs 1237 delegates to earn the party's presidential nomination. His other two presidential rivals Senator Ted Cruz from Texas and Governor John Kasich from Ohio are lagging far behind Trump in delegate count.
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In order to prevent him from becoming a party nominee, Cruz and Kasich have reached a strategic alliance to campaign in different States during the rest of the primaries.
Meanwhile, the controversial real-estate tycoon had to face public protest in California for the second consecutive day.
"That was not the easiest entrance I've ever made," he said when he took the stage.
"My wife called and said there were helicopters following you... And then we went under a fence and through a fence. Oh boy, it felt like I was crossing the border, actually," he said.
Trump's rival Cruz condemned these protestors alleging that they are trying to silence a voice that they do not like.
Cruz is more than 400 delegates away from Trump. The two are battling out in Indiana where the next round of primaries is scheduled.
Trump told his supporters that he is on his way to be the party nomination. Meanwhile Republican women lawmakers urged Trump to have a women on his vice presidential ticket.
"I would suggest a woman, because some of the remarks he has made about women are not going to help him appeal to some of the 53 per cent of the voting populace that are women," Congresswoman Cynthia Lummis said.
Trump would be well served by a running mate with more discipline to balance his unpredictability, she said.