Rep. Steve King has a starring role in a Democratic ad blitz that seeks to hang the Iowa Republican's latest controversial remarks about immigrants around the necks of Republicans trying to appeal to constituencies with heavily Hispanic votes.

The political powerhouse labor union SEIU has just released a Spanish-language ad that targets seven Republican House members, challenging them to say whether they agree with comments that "insult our families" or support legislation that would provide millions of immigrants now living illegally in the United States with a pathway to citizenship. Sunlight spotted the new campaign on Ad Hawk, our mobile website that helps voters identify groups and money behind political advertising. Another Democratic-allied group, the super PAC American Bridge, is taking a similar tack against Republican candidate Ken Cuccinelli in the Virginia governor's race.

King unleashed the latest ad campaign when he suggested during an interview that the so-called DREAMers — illegal immigrants brought here as children and nicknamed after the longstanding, bipartisan legislative effort that seeks to win them a path to citizenship — are being employed as drug mules. That drew immediate condemnation from two top House GOP leaders:  Speaker John Boehner of Ohio and Majority Leader Eric Cantor of Virginia. 

The outspoken Iowan is refusing to back down, however, and Democrats are seizing the opportunity to drive a wedge deeper between the GOP and Hispanic voters.

Four of the seven Republicans targeted in the SEIU ad campaign represent districts that the academic research firm Latino Decisions identified earlier this month as having the potential to flip because of a Hispanic backlash over immigration. They are Reps. Randy Weber, who represents a coastal Texas district with a 19 percent Latino voting age population, according to Latino Decisions; Daniel Webster, whose central Florida district has a 14 percent Latino voting age population; Scott Tipton of Colorado (21 percent), and Gary Miller of California (44 percent).

Other Republicans on the SEIU hit list — Rep. Buck McKeon of California and Nevada Reps. Joe Heck and Mark Amodei — also represent districts where the Hispanic population is higher than the national average. So far no indication that the 60-second spots are intended for broadcast airwaves; no buys have yet shown up on Political Ad Sleuth, which tracks ad filings that the Federal Communications Commission requires to be posted online. But that database does not include cable television stations. And, because only affiliates of the top broadcast networks (ABC, CBS, Fox and NBC) must post their political ad buys to the FCC's online database, the only Spanish-language buys included in Political Ad Sleuth are those provided by volunteers.

And the SEIU has deep enough pockets to make a broadcast buy: Through the end of last year, the labor union had spent more than $275 million helping to elect candidates of its choice to state and federal office, according to records compiled in Influence Explorer.