The Trump campaign announced quietly that it has parted ways with Corey Lewandowski, the fairly unknown and sometimes controversial New Hampshire businessman who shepherded Donald Trump throughout the Republican primary. Lewandwosku, as you may recall, has been the source of both success and problems accompanying the campaign.

Report from the New York Times:

Donald J. Trump is parting ways with his campaign manager, Corey Lewandowski, a move that comes as the presumptive Republican nominee faces challenges as it moves toward the general election.

“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 spokeswoman, Hope Hicks, said in a statement. “The campaign is grateful to Corey for his hard work and dedication and we wish him the best in the future.”

Mr. Trump had faced increasing concerns from allies and donors, as well as his children, about the next phase of the campaign as he pivots toward a general election.

One person briefed on the moves, who asked not to be identified, said the campaign had long planned adjustments to adjust to the needs of a general election campaign.

Mr. Trump has recently seen his standing dropping in recent national polls, and is now facing a barrage of ads by Hillary Clinton and her allies.

Campaign changes when moving from primary mode to general election mode are not unusual as organizations must evolve into fighting new battles on new ground. In this case, it has to lend credibility to reports over the past weeks and months that there was serious disagreements and disconnects between top brass within the Trump campaign.

This from Politico back on May 25, 2016:

Lewandowski’s enemies around the campaign, after months of circulating rumors about his personal life, had a hand in planting a suggestive item about his emotional argument with a campaign staffer in a New York tabloid, according a person with direct knowledge of how the item came to be. And Lewandowski’s rivals also circulated a news report about him shopping a book, in an effort to raise questions about his commitment to Trump’s campaign, according to people familiar with the incident. (Lewandowski denied the report.)

Lewandowski’s supporters, in turn, have urged Trump and his representatives to examine Manafort’s personal life, as well as the lobbying done by Manafort and his associates, according to people on both sides of the Lewandowski-Manafort rift.

Perhaps fittingly, much of the feud has played out on the same social media battleground and using the same conspiratorial tone that Trump himself has exploited to great effect to belittle his rivals.

It appears from these reports that some within the Trump organization have been pushing Lewandowski out the door for weeks, and perhaps Trump’s sagging poll numbers were the nail in his coffin. The Washington Post reports on the historically bad polling:

Not only are Trump’s poll numbers slipping, they are at a low that no one, Republican or Democrat, has seen in the past three election cycles. Looking at the window of time between 200 and 100 days before each of those elections, you can see that Trump has consistently polled worse than George W. Bush in 2004, John McCain in 2008 and Mitt Romney in 2012. He caught up briefly after clinching the GOP nomination — and then sank again.

The margin by which he trails Hillary Clinton now mirrors McCain’s deficit to Barack Obama in 2008. McCain rebounded after the Republican convention — but it’s important to remember that we’re comparing Trump to the worst Republican performance in a general election since 1996.

Some of the concern is, of course, legitimate. Some may be overblown in that Trump has faced seemingly insurmountable mountains before (like becoming the GOP nominee) and ended up prevailing. I think we are witnessing a retooling of his campaign, perhaps with increased advice from ranking Republicans in the RNC who see him as the only viable option short of tearing apart the entire party.

The talk of swapping in another candidate at the convention continues, but none of the proposals are realistic to work, and the new candidate would face a divided GOP electorate and almost certainly go on to lose. The next couple weeks leading up the Republican convention in early July will be a crucial time for Trump to gather with the RNC and formulate a winning strategy for the general election.