(CNN) — A major union pushing for immigration reform will launch a new Spanish-language online ad campaign on Monday that highlights comments by Republican Rep. Steve King of Iowa, which were widely condemned as reprehensible because he portrayed many of the children of undocumented immigrants as drug traffickers.
The ad from the Service Employees International Union will run in the districts of seven House Republicans. They use King's comments from an interview earlier this month with the conservative media outlet Newsmax, where he discussed children of immigrants who want to gain U.S. citizenship if they have graduated high school or served in the military -- the so-called "DREAMers."
King said: "For every one who's a valedictorian, there's another 100 out there who weigh 130 pounds, and they've got calves the size of cantaloupes because they're hauling 75 pounds of marijuana across the desert."
The new ad, called "Otra Vez" -- which means "once again" in English - says, "Once again, the debate over immigration reform has devolved to the lowest level by offensive comments and actions by extreme Republicans in Congress."
It goes on to say, "This is offensive and an insult to our community. It's time that Republicans choose between extremism or progress."
King, one of the most conservative House Republicans on dealing with illegal immigration, came under withering criticism from members of both parties, including House Speaker John Boehner, for the remarks.
But in an interview with CNN's Wolf Blitzer, King did not back down.
"You only get one valedictorian per class per year. And they aren't all DREAMers," he said on Wednesday. "And a lot of other American kids out here that are competing for that valedictorian status. But every night there are dozens and scores of people that are smuggling drugs across our border."
"I've been down there multiple times," King continued. "I've sat along the border at night. I've traveled with the Border Patrol for days on end...This isn't something that just was made up out of thin air. This is something I get from the people enforcing the law down on the border."
SEIU, which is spending five figures for the online buy, is running the ad in the districts of Reps. Cory Miller, R-California; Howard McKeon, R-California; Scott Tipton, R-Colorado; Daniel Webster, R-Florida; Joe Heck, R-Nevada; Mark Amodei, R-Nevada; and Randy Weber, R-Florida -- all who represent districts with substantial Latino populations, union officials say.