It is one thing to think a bill is bad idea. It is another thing actually changing your vote on a candidate because they supported a single piece of legislation. Intensity is what matters.
There is very little data to examine to see if supporting immigration reform could really cost a Republican in a primary, but one place to look for hints is in the 2016 presidential polling. Marco Rubio has been the frontman for immigration, and while immigration reform has been in the news his standing in Iowa has dropped noticeably.
In PPP’s recent polling, Rubio’s share of the vote in Iowa has dropped five points from February to July. Rubio was tied for the lead in February but is now in fourth place in PPP’s newest poll.
Similarly, Rasmussen found that Rubio’s favorable rating among national Republicans has also taken a real hit. It is down 15 points since February.
It is possible the recent bad polls for Rubio are just flukes or his problems stem from unrelated issues, but the actual cause is less important than how his fellow Republicans interpret them. Perception is what is important. If House Republicans look at these numbers and reach the conclusion that publicly supporting comprehensive immigration reform hurt Rubio with the base, it will likely make them less inclined to vote for it.
Photo by Gage Skidmore under Creative Commons license