Rep. Jeff Flake, a Republican seeking to move into a Senate seat this year, won the backing Friday of his state’s two sitting senators, John McCain and Jon Kyl.
The endorsements come as Mr. Flake is trying to derail the primary challenge from Wil Cardon, a businessman who has been on the ropes since the Arizona Republic reported earlier this month that a Subway sandwich shop franchise he co-owned was fined for immigration violations.
Mr. Flake is seeking to replace Mr. Kyl, who is retiring at the end of this year. Mr. Kyl and Mr. McCain both carry substantial weight in the state GOP.
“Jeff stood up to congressional leaders in the House when they were spending too much. They tried to punish and silence him, but Jeff Flake persisted,” Mr. McCain said in endorsing his House colleague.
Mr. Cardon had made immigration a chief attack on Mr. Flake, who has previously sponsored bills that would have granted a path to citizenship to illegal immigrants — much as Mr. McCain had done. Immigration is a toxic issue in Arizona GOP circles.
But the Arizona Republic story, combined with television ads Mr. Flake is running to drive the point home, could muddy the issue.
Arizona’s primary is Aug. 28.