Yes, exactly. The poll is looking at the entire voting population of the district, to the exclusion of the reality that it was the smaller subset of GOP primary voters that made Cantors defeat happen.
So what does the article say was the “cause” of Cantors defeat? Can’t get it to open on my phone ...
This is Politico, here's some of the text:
“Looking just at Republicans in Cantors district, the poll found that 70 percent of GOP registered voters would support such a (generically described immigration) plan, while 27 percent would oppose.
Meanwhile, Cantor was deeply unpopular in his district, the PPP poll found. About 63 percent of those surveyed in his district said they did not approve of the job Cantor has been doing, with 30 percent of registered voters approving. Among Republicans, 43 percent approved of Cantors job performance, while 49 percent disapproved, the survey found.
Cantor didnt lose because of immigration, pollster Tom Jensen wrote in the memo obtained in advance by POLITICO. He lost because of the deep unpopularity of both himself personally and of the Republican House leadership. Even in his conservative district voters still want immigration reform passed, and they want it this year.