As several politicians and pundits using the Boston bombing as a cautionary tale about immigration, public support for immigration reform that includes a path to citizenship for undocumented immigrants has dropped 7 percentage points in less than a month, according to a new poll from Quinnipiac University. There is still a thin majority, 52 percent, that still supports eventual citizenship, but that's down from 59 percent in early April before the bombing on April 15. More than a fifth of respondents, 23 percent, said the Boston marathon bombings made them change their mind on eventual citizenship, though the vast majority, 66 percent, say citizenship would not make us more vulnerable to terrorism.

But that's the case that opponents of immigration reform have been making in the wake of Boston. Iowa Rep. Steve King said the bombing should delay the immigration bill, saying, "We have a real reason in front of us to step back and look at all the things and methods of which people come into this country for whatever their motive is." Texas Rep. Louie Gohmert has suggested al Qaeda operatives are pretending to be Latino to sneak over the border with Mexico. Kentucky Sen. Rand Paul asked why the immigration system allowed people from Chechnya to come to the U.S. -- even though when accused bomber Dzhokhar immigrated, he was 8 years old. Iowa Sen. Chuck Grassley said in an immigration hearing, "How do we ensure that people who wish to do us harm are not eligible for benefits under the immigration laws, including this new bill before us?" Talk radio hosts Laura Ingraham and Mark Levin have raised similar concerns.

We have some clues as to who this messaging is working on. A Pew Research Center survey Republicans oppose the bill by 34 percent, while 30 percent who favor it. But independents who lean Republican oppose it by a number larger number, 51 percent to 19 percent. Why is that? One guess it's those independents who are Tea Partiers unhappy with the GOP.  A recent academic survey of FreedomWorks activists showed that while Tea Partiers do not like Democrats at all, they don't like Republicans much either -- 23 percent identify as "other," rather than Republican. That being said, King has a chance to spread his "messaging." Pew also found that a plurality of voters, 38 percent, don't know what they think of the Senate bill. Two weeks ago, Iowa Rep Steve King said that his anti-immigration allies didn't yet have the votes, "But it's about messaging and the American people need to wake up to what's going on."