2 completely different versions of Donald Trump have been showing up on the campaign trail

While railing against the "disaster" that is the Trans-Pacific Partnership trade deal, Donald Trump fell back on a controversial rhetorical device that's become fairly common in his speeches.

"The Trans-Pacific Partnership is another disaster done and pushed by special interests who want to rape our country - just a continuing rape of our country," Trump said during a rally in Ohio.

He continued: "That's what it is, too. It's a harsh word. It's a rape of our country."

And with that, Trump undid the progress he'd made toward keeping his campaign on a straight and narrow messaging path.

It was Trump's first rally since firing campaign manager Corey Lewandowski. In the days since Trump overhauled his team, adding several communications staffers and strategists who could help professionalize the operation, political observers saw a noticeable difference in Trump's public statements.

He gave a polished speech in New York in June skewering Hillary Clinton's economic policies. He stayed mostly on script and didn't take questions from reporters afterward. His tweets started sounding more coherent, with less errant punctuation and typos. And his campaign started sending out rapid-response emails to respond to Clinton's attacks.

But in his rallies, Trump is the same candidate he's always been, stoking the energy of the crowd with inflammatory statements atypical of a major-party candidate running for the highest office in the country.

During a campaign event in New Hampshire on Thursday, while a plane buzzed overhead, Trump joked that Mexico might be getting ready to attack the US.

"That could be a Mexican plane up there," Trump said. "They're getting ready to attack."

Trump was clearly being facetious, but the comment still goes to show that Trump isn't quite as disciplined as his recent teleprompter speeches and rapid-response email blasts suggest. He's still straddling both strategies, appearing restrained and "presidential" in some settings while letting loose in others. It suggests a bit of an identity crisis in his campaign.

"His behavior has to change. And we saw yesterday that it still is not changing," GOP strategist and commentator Evan Siegfried told Business Insider, referring to Trump's New Hampshire event.

And even if Trump did start committing more to rehabilitating his image before the November election, it might be too late for many voters.

"The speech he gave about Hillary Clinton was actually a good speech," said Siegfried, who wrote the forthcoming book GOP GPS: How to Find the Millennials and Urban Voters the Republican Party Needs to Survive. "However, it's like the boy who cried wolf. Because he's gone out and said so many crazy things, it takes away all the impact and everybody says, 'oh it's Trump being crazy.'"

Trump might have damaged his credibility past the point of no return.

"I don't think Trump himself can recover from it because even now, the campaign won't do the basic required to confirm credibility," Siegfried said.

"His record of charitable giving still has not produced any proof that he's ever given money to charity. And then you have also, he says he forgave the loan he gave to the campaign, but the campaign won't furnish proof of it."

Still, when it comes to taming his rhetoric in certain arenas, now is better than never, according to Matt Mackowiak, a political strategist and president of the Potomac Strategy Group.

"It's never the wrong time to start," Mackowiak told Business Insider.

Now it's a matter of seeing whether Trump can stay on message and avoid creating too many distractions.

"A more disciplined, more professional campaign is absolutely necessary," Mackowiak said. "But honestly, it's always been less about the campaign itself and more about the candidate. What is most important is to see sustained discipline on Trump's part in terms of just really staying focused, not creating distractions, not creating controversies and problems."

So far, Trump hasn't been able to do that.

"He seems to have the total inability to go through one day as a normal candidate," said Mackowiak, who also referenced Trump's Mexican plane joke from this week. "That was totally unnecessary. I don't know if he thought it was funny or something."

Siegfried isn't optimistic that Trump will be able to turn it around.

"He said he's going to keep doing what he's been doing and he's not going to change," Siegfried said. "So you can bring on the 'A-Team' of communications people but they'll still be playing defense to every single one of Trump's missteps."

He added: "Discipline is not a word associated with Donald Trump."

Rallies seem to provide the greatest potential for Trump to do damage to himself.

While Trump's prepared speeches give him a veneer of credibility as the GOP's standard-bearer, he can easily derail that image with one outrageous statement at a rally.

"The question is can he be that disciplined in a rally without prepared text," Mackowiak said. "That to me is the next measuring stick that they've got to find a way to get to, and I don't know whether he has that in him."

Trump's propensity for making controversial statements at his rallies might indicate a lack of knowledge about the issues.

"The problem is he can't fall back on substance to fill an hour," Mackowiak said. "[T]hat's part of why he chooses to spend time attacking his Republican opponents and other rivals, because he doesn't have enough substance that he can kind of riff" on that."

Both Mackowiak and Siegfried mentioned the impact that Trump's nontraditional campaign could have on fundraising.

A Federal Elections Commission report released last month revealed Trump had only $1.3 million cash on hand, compared to Clinton's $42.5 million.

"He needs to actually start raising money and getting donors," Siegfried said. "Republican donors … are either sitting this one out or directly giving to Senate candidates."

Trump has reportedly been having trouble soliciting money from some big-name Republican donors. Billionaire hedge fund manager Paul Singer, a major GOP donor, is part of the "Never Trump" movement and said this week that Trump's economic policies would "guarantee" a "widespread global depression."

"What they're getting right now is low-hanging fruit," Mackowiak said. "People who already support him and are drawn to his celebrity."

Siegfried put it in more colorful terms.

"The only way that he can woo those big-name donors would be with a roofie," he said. "They're done. These big-name Republican donors, they got to where they are by being smart with money. And they know a bad investment when they see it. Donald Trump is a terrible investment."

Trump's brash style could also hurt his chances of winning votes in the general election. Clinton, the presumptive Democratic nominee for president, has beaten Trump in nearly all head-to-head polls for weeks.

"And I think a lot of pundits, including the Trump campaign, completely misunderstood that the nature of the general electorate is so different from the Republican primary electorate - that, you know, the same old Trump shtick wasn't going to work," Tim Miller, who served as Jeb Bush's communications director during his 2016 presidential run, told Business Insider last month.

"This was extremely predictable," he said, referring to Trump's plummeting poll numbers. "The general electorate was increasingly turned off by him even as he was winning primary elections. I don't like to give credence to the idea that he was making some sort of strategic communications calculation. He wasn't. He was just being Trump. This is Trump au naturel."