As the LA Times noted in it's recent article titled Trump's Iowa loss reveals campaign vulnerabilities,
Trump's second-place finish in Iowa exposed an array of weaknesses in his campaign: His flashiness has started to grate on supporters.... He's proved vulnerable to attacks on his ideological purity. And he failed to put together an effective ground operation.... In the end, the celebrity candidate was more susceptible to the normal rules of politics than many expected.
As his supporters tire of tough talk without concrete proposals, Trump may end up "marginalized like independent H. Ross Perot in 1992," the Times suggests.
Meanwhile, the NY Times reports that Trump's Iowa loss has encouraged Republican leaders opposed to to his candidacy, "as the party establishment closes ranks around a smaller number of candidates, and Mr. Trump faces new threats from the right."
And as the NY Times Nate Cohn observed, Trump supporters came out in numbers in Iowa, yet he "fell short."
He lost among voters who decided over the last month by a wide margin, and he took third place among voters who had previously participated in the caucuses. Mr. Trump fared particularly poorly among voters who decided over the last week — since his decision not to participate in the final presidential debate before the caucuses.