Donald Trump is marching toward the Republican presidential nomination, sweeping all five primaries this week. And despite the persistent efforts of the GOP establishment to stop him, Trump’s poll numbers keep climbing. The best chance for derailing his path to the nomination will likely be Trump himself.

Trump’s popularity among Republican primary voters centers on his bombastic personality and his propensity for saying whatever pops into his head. Voters have equated that with authenticity.

But last Friday, Trump’s new campaign guru, Paul Manafort, told a Republican National Committee meeting in Florida that Trump would change his unfiltered ways if he were to win the nomination, assuring them the candidate would become more presidential.

That may be soothing for uneasy party leaders. But what about Trump supporters who gave him their votes in large part because they like him just the way he is — or the way they think he is? Take that away, and there isn’t much left.

Trump is style over substance. Over the years, on major issues from Obamacare to abortion, he has changed his mind over and over again. Similarly, he’s flip-flopped on immigration, ISIS and foreign policy.

Trump is a reality TV show star, and he’s running a campaign that’s hugely entertaining. And there’s no denying it is resonating with voters who are angry and ready for something vastly different.

But do they really know what they’re getting in Donald Trump? In light of Manafort’s revelation, that’s a question his supporters should be asking.

Following Manafort’s comments, Trump has tried mightily to reassure his fans that he’s the same boorish guy. On Monday, he bashed Ohio Gov. John Kasich, one of Trump’s two remaining rivals for the GOP nomination, for how he eats his pancakes.

“Did you see him? He has a news conference all the time when he’s eating. I have never seen a human being eat in such a disgusting fashion,” Trump said in Rhode Island.

After Tuesday night’s impressive wins, he again enraged women by declaring the only thing Hillary Clinton has going for her is “the woman card.”

Trump says he can do better, but doesn’t really want to.

“I can do it,” he said during a campaign rally over the weekend in Waterbury, Conn., while mugging like a puckish child. “I’m like a really smart person. Like a lot of you people. Presidential is easy.”

But he also acknowledged, “If I acted presidential, I guarantee I wouldn’t be here.”

Trump is right about that.

And increasingly, Republicans who looked to this summer’s national convention in Cleveland to finally stop Trump are seeing that hope slip away.

“Average voters do not want a contested convention,” says Michigan pollster Steve Mitchell. “In order to stop that, enough voters may decide to go for Trump to avoid a deadly convention battle.”

GOP political strategist Katie Packer, who started an anti-Trump political action committee, says despite Manafort’s reassurances, it isn’t possible to remake Trump.

The truth of this reality show is that with the campaign winding down, voters still don’t know the real Donald Trump, or if the candidate even knows who he is himself.

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