WASHINGTON — The candidates atop the GOP presidential field are ramping up political attacks aimed at Muslims, a move designed to appeal to hardline conservatives. But party elders worry that escalating anti-immigrant rhetoric could cost Republicans the White House in 2016.

The aggressive words, in particular from front-runners Donald Trump and Ben Carson, have exacerbated a widening rift between the GOP’s pragmatic and ideological wings as the party tries to avoid losing a third consecutive presidential election.

His relationship with the nation’s Hispanic community already strained, Trump vowed on Wednesday to deport any Syrian refugee taken in by the U.S. Most likely would be Muslim, and Trump warned they could be Islamic State militants in disguise.

“If I win, they’re going back,” the billionaire businessman said.

Carson, a retired neurosurgeon, launched a petition on Thursday challenging the nation’s largest Muslim advocacy group’s tax-exempt status, escalating his ongoing rift with the U.S. Muslim community.

The Council on American-Islamic Relations last month called for Carson to quit the presidential race after he said a Muslim should not serve as president. He has since clarified his position, stating he wouldn’t support a radical Muslim who did not support the Constitution. And in a Thursday radio interview, Carson said the same standard should apply to a Supreme Court justice.

He said Islam is “a lifestyle” that he’d “need to know about” before making an appointment to the nation’s highest court.