A pro-immigration reform group founded by Mark Zuckerberg is issuing an unsubtle warning to vulnerable Republicans about the possible electoral consquences if no further progress is made on overhauling the immigration system before November.

The Council for American Job Growth, a progressive affiliate of Zuckerberg's nonpartisan FWD.us, released the results of a poll Tuesday they conducted in ten swing districts currently represented by incumbent Republicans that have significant Hispanic and Asian-American voting populations.

The survey simulated the way this fall’s campaign might unfold if a group like Fwd.us launched pro-immigration advertisements in these districts, linking the Republican incumbents to inaction on immigration reform.

After being read a sample negative advertisement linking the Republican incumbent to GOP leadership to, for example, “punishing… young immigrants and taking away their opportunity to make a positive contribution to society” by blocking a bill that aided DREAMers, vote shares for the incumbent dropped from 51 percent to 45 percent.

Another negative advertisement read to respondents said that the Republican incumbent was “blocking an immigration bill that would allow undocumented immigrants to contact law enforcement to report crimes like domestic violence without fear of deportation for them and their family.”

Among independents, the vote shares of Republican incumbents dropped seven percentage points after these messages were read.

“The data makes clear that there are real electoral consequences for Republicans in these districts, because voters tie them to their party's own failure to take action on passing reform legislation,” FWD.us spokeswoman Kate Hansen said.

While FWD.us has already spent millions on advertisements in 2014, it’s unclear whether the poll’s implicit warning has teeth – the group wouldn’t say whether it would launch targeted ads similar to those tested in the poll.

Overall, respondents in the 10 GOP swing districts broadly supported immigration reform – 76 percent supported a proposal including a pathway to citizenship and border security, while 19 percent opposed it. And among these same voters, a majority – 58 percent – said that it was personally important to them that Congress fix America’s immigration’s system.