In an abrupt and unexpected move Monday morning, the Donald Trump presidential campaign announced that it had parted ways with campaign manager Corey Lewandowski, the New Hampshire Republican who guided the presumptive Republican presidential nominee to key early victories in the GOP primary.

Reading the tea leaves to determine the reasons why things happen in the Trump campaign is a tricky business, not least because it’s unclear that the things that motivate most politicians are the same as those that motivate Trump.

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Lewandowski is a prime example. The man had assault charges filed against him by a news reporter after he repeatedly denied manhandling her at a press conference. The presidential candidate hasn’t been born who doesn’t jettison Lewandowski immediately after that, if only to preserve relations with the media. Except for Trump.

So why oust Lewandowski now? There are at least a few plausible explanations.

1. Run-of-the-mill campaign shakeup.

Given the terrible few weeks that Trump has had -- from attacks on a federal judge over his heritage to multiple missteps responding to the massacre in an Orlando nightclub last week -- it wouldn’t be shocking to learn that the decision to replace Lewandowski was a simple effort to reset the Trump campaign.

Like a struggling baseball team that decides to set a new tone by replacing the manager, political campaigns have a long history of “shakeups” meant to correct course. They are never a good sign, but they aren’t necessarily fatal, either. John McCain fired his campaign director in advance of the 2008 Republican primary and went on to win the nomination.

2. Weeks of internal battles had become a distraction.

When Trump brought longtime GOP operative Paul Manafort on board to help guide his strategy for what then looked as though it might be a contested Republican convention, the stories coming out of the campaign about tension between the new hire and Lewandowski were frequent and convincing.

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This despite Trump’s claim to Bloomberg earlier this month that “Corey and Paul get along great.”

Over the weekend, another raft of stories about infighting and dysfunction arising from the existence of competing power bases within camp Trump hit the media. It’s possible that it finally became too much to tolerate, even for Trump, who seems to have a preternatural tolerance for strife and discord.

3. Lewandowski was ousted as a peace offering to an angry GOP establishment.

The Trump campaign’s increasingly fraught relationship with the Republican Party establishment, particularly the Republican National Committee and top elected leaders, is growing into a serious problem for his campaign. Trump ran as an outsider, in a campaign choreographed in large part by Lewandowski. He spent months attacking the establishment for “rigging” the primaries and delegate selection processes against him.

Even after becoming the nominee, Trump’s attacks continued. As recently as Saturday, Trump continued to claim that he could win the election without the support of the GOP establishment.

Maybe someone he trusts finally sat Trump down and explained reality. His utter lack of a national campaign infrastructure and his apparent inability or unwillingness to do the fundraising that a presidential candidacy requires combine to make him uniquely reliant on the RNC and the goodwill of elected Republicans.

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Perhaps getting rid of the guy who was running the show when Trump’s anti GOP rhetoric was at its height is meant as a sign of the long-awaited “pivot” toward a more traditional campaign.

A sign that this might be the best explanation of Lewandowski’s ouster is how the campaign handled it. Trump is famous for firing people and loves to tweet about how someone who has offended him was “fired like a dog.”

Lewandowski, though, was sent packing with a verbal pat on the head from Trump’s communications director, Hope Hicks, who wrote in a statement, “The Donald J. Trump Campaign for President, which has set a historic record in the Republican primary having received almost 14 million votes, has today announced that Corey Lewandowski will no longer be working with the campaign ... The campaign is grateful to Corey for his hard work and dedication and we wish him the best in the future.”