But rather than admit defeat, Trump struck back by releasing a statement accusing "Lyin' Ted" of illegally coordinating with the super PAC that’s supporting the Cruz campaign. The accusation has not been confirmed, and Cruz's senior adviser, Jason Miller, didn't directly respond to the charge, only portraying it as an example of Trump's being Trump.
"Donald Trump has a real problem when he gets his tail kicked and that's exactly what happened tonight," Miller said Tuesday.
A state poll a week before the primary had Cruz beating Trump by 10 points, but the final total came out closer to a 13-point gap between the two.
ABC News estimates that Trump was only awarded six of the 42 delegates available in Wisconsin; Cruz was awarded 36 delegates.
The upshot is that speculation about a possible contested convention becomes more real.
Trump has a total 743 delegates and Cruz has 517 total delegates, which would mean they have to get, respectively, 60 percent and 87 percent of the remaining delegates from the upcoming state contests to secure the nomination before the convention.
"To quote 'Invictus,' he is the master of his fate, and he is the master of his soul," Dowd said.