Melania Trump's speech at the GOP convention in Cleveland is drawing comparisons to Michelle Obama's speech at the 2008 Democratic National Convention in Denver. Here's a side-by-side look at both. (Jenny Starrs/The Washington Post)

Donald Trump prides himself on flying by the seat of his pants. By doing things — in life and in politics — that freak out the squares. By being different and, in his mind, better.

That unpredictability has served him remarkably well in the presidential campaign to date; it kept his opponents in the Republican primary off balance and appealed to voters who wanted something, anything, different from politics as usual.

But unpredictability and rejecting all norms of "how things are done" have a darker side, too. And that darker side was exposed late Monday night when it became clear that portions of Melania Trump's speech to the Republican National Convention had been lifted from Michelle Obama's Democratic convention address eight years earlier.

The Trump campaign is spinning this as (a) nothing more than a few borrowed words and phrases (Chris Christie said that 93 percent of the speech was Melania's own) and (b) a secret plot by Hillary Clinton's campaign to discredit another powerful woman. This from Trump campaign manager Paul Manafort:

Speaking at a July 19 press briefing, Donald Trump's campaign chair Paul Manafort defended Melania Trump's speech at the Republican National Convention against allegations of plagiarism. (Reuters)

Here's the thing: Plagiarism means borrowing words that aren't yours. It doesn't matter whether that's 1 percent of the words or 99 percent of the words. Unless you say "And, in the words of ___________," you can't use someone else's words. It's that simple.

Ask yourself this: If it came out that I had plagiarized two or three paragraphs in a much longer story, would you be cool with that? Do you think my bosses would be?

Right.

What all of the excuses being offered by the Trump campaign are meant to cover up is the fact that someone, somewhere, needed to go through Melania Trump's speech with a fine-toothed comb before she delivered it. Then they needed to go through it again. And again. Hell, run each phrase through Google and see what pops up. This isn't that hard. The Internet exists. Use it.

Given that, how could something like his happen? Because Trump has set the example from the top: Say stuff and figure it out. And it has worked, which only affirms the idea that he can say and do whatever and not suffer any consequences. That he doesn't need the size staff that other campaigns have traditionally carried because he can do it better and simpler.

The problem with that is, well, what happened on Monday night. The candidate's spouse, delivering one of the three or four most important speeches of the entire convention, got caught lifting lines. This is a GIANT embarrassment for Trump and one that you can be sure he will be livid about — and be looking for a fall guy.

But the real blame lies with Trump. This is the campaign he wanted, the campaign he prided himself on running. Zigging when everyone else zags works — until it doesn't. Unpredictability isn't a strategy. Trump learned that the hard way Monday night.