Donald Trump's defeat in the Wisconsin GOP primary was a turning point that could derail the business magnate's campaign, Bush 43 political director Sara Fagen said Wednesday.
"He is a sore loser, and he has proven it time and time again. This is a person who has not built a campaign infrastructure and now the rubber hits the road in these delegate contests. He's pointing fingers, he's lashing out perhaps even more so than he's done in the past," Fagen told CNBC's "Squawk on the Street."
"Last night I think was a real turning point in the Republican race. Donald Trump can now, because of his devastating lost last night, win every single delegate in New York and most of the delegates in the New Jersey and Pennsylvania and many of the delegates in the upcoming contests, and still not have enough delegates on June 7, the last day of voting," added Fagen, who is now a partner with the Washington consultancy firm DDC Advocacy. "I think it is now inevitable that this will be an open convention."
Sen. Ted Cruz of Texas handily defeated Trump in Wisconsin on Tuesday, but the billionaire businessman is still leading with 753 delegates to Cruz's 514 in the race for the 1,237 needed for the nomination.