This post has been updated with new information throughout.
But there's another problem. Notice the letterhead of the statement: The Trump Organization, which is to say Donald Trump's personal business. And notice how McIver describes herself: As an employee of the Trump Organization, not the campaign.
If Trump used corporate resources to write a political speech, that could be illegal.
"On the face of it, this looks like a corporate violation," explained Lawrence Noble, general counsel for the Campaign Legal Center. And that is "a violation of federal law. It can result in civil penalties to the corporation and the campaign." If the campaign used corporate resources "willingly and knowingly," the offense is a criminal one.
Noble notes, however, that the campaign has regularly used corporate staff for the campaign -- but have properly accounted for that use by paying the staff from the campaign. Trump's campaign can use Trump Organization staffers if those staffers are paid for that work by the campaign.
"It's very hard to tell exactly what's going on," Noble said, "but it's possible that what they're doing is paying in advance for the use of staff." Campaign filings show that the Trump campaign has done this frequently; as long as the staff are paid for their campaign work -- by the campaign, and in advance -- it's allowed. The campaign also has to compensate the corporation for any resources used: A computer, a printer, a desk. If Trump For President anticipated using McIver and then wrote a check to Trump Org for her time and electricity and so on, that angle is covered. (The way that campaign finance reports are filed, though, it's hard to know if this is what happened, even after the fact.)
Update: During a press conference on Thursday, Trump campaign manager Paul Manafort said at a press conference that McIver wasn't known to the campaign staff. "Look, none of us knew that [McIver] was even involved in the process," he said, as reported by Politico. "I asked Melania Trump what the story was about. She insisted and I believe her that these were her words, and the statement that [McIver] gave yesterday is consistent with that." That none of the people involved with the campaign knew McIver was working on the speech, per the campaign manager, strongly suggests that she was not paid by the campaign in advance as required by federal law.
That the letter is on Trump Organization letterhead is also problem by itself. "The Trump Organization should not be providing anything to the campaign that it's not getting paid for," Noble said -- including letterhead. It also reinforces the idea that McIver wasn't working for the campaign at all, as legally required. The letter contains no suggestion that McIver was a campaign employee at any point. Noble points out that she offered to resign her position, but which position? For it to have been legal, she was working for the campaign -- but it seems clear that she offered to resign from her theoretically unrelated Trump Organization job. What we would have expected is a letter on campaign letterhead talking about how McIver as a campaign employee accidentally included parts of Obama's speech. None of that is the case.
Update: The campaign's most recent filing, covering the month of June, also doesn't show any payments to McIver.
This sort of murkiness doesn't usually arise. Most presidential candidates don't have a separate, larger operation that they are trying to manage at the same time as their political bids. That Trump does makes overlap like this more of a problem.
"He's apparently using his company to an extent that we've never seen before in a presidential candidate, and it causes all of these issues," Noble said. This isn't the first time that questions about the use of organizational resources has come up, by the way. In January, a PAC aligned with Jeb Bush filed a complaint against Trump's campaign for using a Trump organization attorney.
It took Trump's campaign two days to finally put the plagiarism question to rest. In doing so, though, they may have just raised a whole new set of questions.
Update: On Thursday morning, a Democratic PAC filed a complaint with the FEC centered on the use of McIver by the campaign.