Rep. Eric Cantor (R-VA) announced on Wednesday that he was stepping down from his role as majority leader after his historic defeat in the Republican primary on Tuesday night.  He will stay on as majority leader through the end of July.

Cantor, 51, had been in Congress for more than 13 years now. But in all that time, his only close election was his first one–the 2000 Republican primary, which he won by less than one percentage point. Since then, he had always won by a large margin. In some years, he faced no primary opponent at all.

Cantor was defeated by Dave Brat, 49, an economist at Randolph-Macon College in Ashland, Virginia, a purist conservative, who made his opposition to immigration reform a central focus of his race, slamming Cantor for agreeing to even consider piecemeal proposals.  In addition, there was a perception among some Virginia Republicans that Cantor had grown distant and did not visit his district enough.

Cantor’s statement prompted Republican lawmakers to launch bids to succeed Cantor, who had been the heir apparent to House Speaker John A Boehner (R-OH).  Cantor put his “full support” behind his longtime lieutenant Majority Whip Kevin McCarthy (R-CA), who represents the conservative establishment within the Republican Party.  Immediately McCarthy faced  threats from Representative Jeb Hensarling (R-TX), head of the Financial Services Committee and Pete Sessions (R-TX), head of the Rules Committee.  Sessions is arguing that his work during the 2010 elections as chairman of the National Republican Congressional Committee makes him ready to manage the House floor.

Hoping to avoid a long and potentially divisive campaign period, Boehner’s leadership team scheduled a relatively speedy race with secret ballots to be cast June 19, giving contestants only eight days to make their cases.  With his own future under scrutiny, Boehner indicated that he was inclined to seek another term instead of retiring at the end of the year.

Cantor told reporters after this announcement to step down that he remains hopeful that the coming leadership votes will not split the party ahead of what could be a solid showing in the November election.  “I hope that all Republicans will put minor differences aside and help elect a Republican House and Senate,” he said.

Meanwhile, polls on both the left and right indicate that immigration was not the central issue that led to Cantor’s downfall.  A conservative-sponsored poll showed that only 22 percent of Virginia residents who voted for Brat, cited immigration as the primary reason for their vote.  About 77 percent cited other factors, such as the Republican leader’s focus on national politics instead of local issues.  “Amnesty” polled last of five issues GOP voters considered harmful.  Instead, nearly 73 percent of voters supported a proposal that would secure the border, go after employers who hire illegal immigrants, and establish a pathway to citizenship after certain requirements are met.

Those results resemble findings in a poll commissioned by the liberal advocacy group, called  Americans United for Change.  That poll noted about 72 percent of registered voters in Cantor’s district support reforms.  So, it appears that immigration had a smaller impact on the race than initially perceived.