New Hampshire GOP chair Jennifer Horn said in a statement that Trump's immigration plan is "un-Republican. It is unconstitutional. And it is un-American."
Matt Moore, the chairman of the South Carolina GOP, tweeted that Trump's latest anti-Muslim comments sent a "shiver down [his] spine."
According to the HuffPost pollster, which averages publicly available polling data, Trump currently leads his fellow rivals in New Hampshire by double digits. In South Carolina, Trump is up on the pack by approximately 5 percentage points.
The Republican National Committee remained conspicuously silent on Trump's proposal Monday evening. It did, however, announce that the candidate would no longer be appearing at an RNC fundraiser in New York City as previously scheduled.
Iowa GOP Chair Jeff Kaufmann seemingly reacted to Trump's plan on Twitter as well, but he did so without specifically calling out the real estate mogul by his name.
At a campaign rally in South Carolina on Monday, Trump doubled down on his proposal to bar Muslims from entering the U.S.
“We have no choice. We. Have. No. Choice," Trump said, earning a standing ovation.
The presidential hopeful defended himself from nearly unanimous criticism from Democratic and Republican presidential candidates, some of whom called his proposal contrary to American ideals.
"Yes, we have to look at mosques. We have to respect mosques, but we have to look at mosques," he said.
"Don’t worry about profiling," he told his supporters. "I promise I will defend you from profiling."
This story has been updated to include comments from Kaufmann.
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