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People should quit underestimating Donald Trump, because the real estate mogul might just be able to snatch up the Republican presidential nomination, says former Vice President Dan Quayle.

“I think people are going to have to take him a lot more seriously than they have in the past,” Quayle told Neil Cavuto in an interview Wednesday.

He pointed out that not only does Trump have the lead in most polls, but also most people didn’t believe he would even run a short while ago.

“He’s in,” said Quayle. “And he’s going to be around for a long time.”

“I think he possibly could win the nomination,” he added.

But it won’t be easy for Trump to pull off, said Quayle, predicting that the billionaire would likely “be challenged” by an establishment favorite.

The challenger for the nomination would then come down to three candidates, said the former vice president: former Florida Gov. Jeb Bush, Florida Sen. Marco Rubio and Texas Sen. Ted Cruz.

“I would think one of those three would be the contender along with Donald Trump,” Quayle said.

Watch Quayle’s interview in the clips above and below.

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