Lewandowski has been with Trump since the beginning of his unexpected political rise to the top of the presidential election process. He has also been at odds with other factions within the campaign on the direction forward, especially as Trump has struggled to gain his footing in the general election. In what appears to be a surprise move, Lewandowski was with Trump at campaign events and fundraisers as recently as this weekend.
Some divisions within a presidential campaign are almost inevitable, but the civil war within Donald Trump's operation reached an untenable level quite a while ago. One recent report described "TrumpWorld" as "a seething mosh pit." In a separate report, an operative close to the campaign described the operation as "a total cage fight."
As regular readers know, Team Trump is divided into two warring factions: a contingent that sides with Campaign Manager Corey Lewandowski and another backing Campaign Chairman Paul Manafort. Eventually, something had to give. This morning, something did: NBC News confirmed that Lewandowski is out.
There's been no shortage of controversy surrounding Lewandowski, and he even faced a criminal charge after a confrontation with a reporter a few months ago. Around the same time, other Trump staffers "expressed concerns" about Lewandowski's "quick temper and heavy-handed leadership." Some Trump aides reportedly even "planned a coup against him."
At the time, Trump said he would remain loyal to the campaign manager who remained loyal to him. But that was when the New York Republican was still riding high; now that Trump is losing, it's a very different story.
NBC News' Ali Vitali asked a source within the campaign if other Trump staffers had been notified of the decision to oust Lewandowski. The source said it's "bedlam in the Trump campaign. No one knows what is happening."
Those are not phrases generally associated with a successful political enterprise.
In fairness, candidates replacing his or her campaign manager during the race isn't unprecedented. As we discussed in April, Howard Dean's 2004 campaign actually went trough three different campaign managers over the course of a year, with the last switch coming in late January. Less than a month later, Dean ended his candidacy.
In the same cycle, John Kerry replaced his campaign manager in November 2003. Two months later, Kerry won the Iowa caucuses and the New Hampshire primary, en route to winning the Democratic nomination with relative ease.
What's unusual about Team Trump, however, is the timing: it's mid-June. The primaries are over. The Republican National Convention kicks off in less than a month. For a major-party presumptive nominee to oust his campaign manager at this stage is emblematic of an amateurish national operation that's struggling to find its footing.
By any fair measure, the Trump campaign is an organizational and managerial train wreck. Some kind of shake-up was inevitable.
Remember last week when the GOP candidate said the gunman in Orlando's mass shooting was born in Afghanistan? This happened because staffers "accidentally uploaded the wrong version of the speech into the teleprompters." It's the sort of thing that happens when a candidate runs for president with an unprepared, vestigial staff.
The Boston Globe reported this morning that there's a deliberate strategy playing out: "[C]ampaign officials concede the presumptive presidential nominee has little desire or capacity to construct the kind of massive national operation that has come to define modern-day White House campaigns."
A senior Trump aide told the newspaper, ''It would be disingenuous and wrongheaded to take a playbook that has been used over and over again.''
The trouble, of course, is that playbook has been used to win national campaigns. Presidents have relied on that playbook to make it to the Oval Office. Abandoning successful blueprints, just for the sake of abandoning successful blueprints, is a recipe for failure.
There's no guarantee that Trump's operation will be any better with a new campaign manager -- when the biggest problem with a campaign is the candidate, even competent staffers don't have a lot to work with -- but there's little doubt Trump is on track for an embarrassing defeat. Will Lewandowski's successor turn things around? Stay tuned.
* Update: In February, following a staff shake-up in Ted Cruz's operation, Trump said on Twitter, "Wow was Ted Cruz disloyal to his very capable director of communication. He used him as a scape goat - fired like a dog! Ted panicked." Noted without comment.