Story highlights Rep. Steve King, an influential Iowa conservative, called Donald Trump a GOP leader on immigration

King said he may endorse a presidential candidate, but hasn't yet settled on a pick

Des Moines, Iowa (CNN) Rep. Steve King, an influential conservative Republican from Iowa, said Monday he believes Donald Trump is leading the Republican presidential field when it comes to immigration.

"I think today he is the leader on immigration," King told CNN in an interview at the Iowa State Fair. "There's no question about that."

King said he was "very happy" to see Trump release his policy paper outlining his position on immigration and border security on Sunday and said many of the positions are based on bills and amendments he's introduced in Congress.

"If there's going to be competition on the immigration issue among the other candidates, who's going to stand up now and say, 'I think we really ought to nominate someone who's for amnesty'?" King said.

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