Rep. Steve King (R-Iowa) has defended his remarks, saying his description of some immigrants as “drug mules” came from talking with Border Patrol agents. (Drew Angerer/GETTY IMAGES)

House Republican leaders are denouncing one of their own for remarks made last week that disparaged most illegal immigrants as drug smugglers. The comments by Rep. Steve King (Iowa) came as the GOP is trying to improve its image and political prospects among the fast-growing Latino community.

King, one of the House’s most vocal opponents of immigration reform, told the conservative Web site Newsmax that for every young illegal immigrant who becomes a valedictorian, “there’s another 100 out there that — they weigh 130 pounds, and they’ve got calves the size of cantaloupes because they’re hauling 75 pounds of marijuana across the desert.”

The Iowa lawmaker has been at the forefront of a group of House conservatives who are staunchly opposed to any path to citizenship for immigrants who are in the country illegally, but his rancor has begun to alarm top Republicans.

As the immigration reform debate stretches on, some GOP leaders are concerned that overzealous anti-immigration voices could further harm the party’s standing with Latino and Asian voters, who overwhelmingly supported President Obama’s reelection last fall.

The House is deliberating a series of smaller-scale immigration proposals, eschewing the comprehensive bill approved last month by the Senate that includes a path to citizenship for up to 11 million undocumented immigrants.

Speaker John A. Boehner (R-Ohio) and Majority Leader Eric Cantor (R-Va.) condemned King on Tuesday. On Wednesday, Rep. Raul R. Labrador (R-Idaho), who was born in Puerto Rico, called King’s remarks, made last Thursday, “irresponsible and reprehensible.”

“What he said was out of touch with the conference. There’s nobody in the conference who would say such a thing, and I hope that he, if he thought about it, he wouldn’t say such a thing again,” added Labrador, who spent months working with seven House colleagues on a comprehensive immigration reform bill before dropping out of the stalled effort last month.

King’s office did not respond to a request for comment. But in an appearance on Radio Iowa on Tuesday evening, King stood by his remarks, saying his description of some immigrants as “drug mules” came from talking with Border Patrol agents.

He said that if immigration reform proponents “choose to characterize this about valedictorians, I gave them a different image that we need to be thinking about, because we just simply can’t be passing legislation looking only at one component of what would be millions of people.”

While most House Republicans oppose a path to citizenship, Cantor is working on a proposal that would offer potential citizenship to young people brought to the country illegally as children, a population estimated to be 1.7 million. That legislation is expected to be modeled after the failed DREAM Act.

Some Republicans think it is crucial for the GOP to support large-scale immigration reform to get the issue off the table for the party’s presidential nominee in 2016. But the party is bitterly divided over how far to go.

Republican National Committee Chairman Reince Priebus told a conference of Latino officials last month that the party is reshaping its outreach to minority groups. “In America, it doesn’t matter where you come from; it matters where you’re going,” he said.

Democrats pounced on King’s remarks Wednesday, with six members of the Congressional Hispanic Caucus taking to the House floor to speak out against him. Rep. Albio Sires (N.J.), whose family immigrated from Cuba, said that his parents “brought me here for the freedom, they brought me here for the opportunities, and they never told me to strap 75 pounds of marijuana on my thighs so we could sell it in America. It is disgraceful that a member of this body would disgrace the House and this country with remarks like that.”

The White House, which has been eager to increase pressure on the House to support the Senate’s immigration bill, also took the opportunity to chastise King.

“Congressman King’s comments were extremely unfortunate,” press secretary Jay Carney said aboard Air Force One, as Obama traveled to Illinois for a speech on the economy. “They certainly don’t help any efforts by Republicans to improve their standing among Hispanic Americans.”

Ed O’Keefe contributed to this report.