Tea Party-backed newcomer David Brat is winning with a large margin of victory over House Majority Leader Eric Cantor tonight in the Virginia primaries, with a campaign from the right that focused on the Republican leader's support for comprehensive immigration reform. It's no understatement to say that very few people saw this coming (ahem). As of 8 PM, Cantor had 43.8 percent of the vote, while Brat was pulling in 56.2 percent. That's with 71 percent of precincts reporting, according to Politico. The AP called the race for Brat soon after. 

Cantor's internal polling put the candidate ahead with more than a 30-point margin of victory as late as last week, as the Washington Post reported at the time. 

The last time Cantor was challenged for his 7th District seat, he won with nearly 80 percent of the vote. So until the votes started coming in Tuesday evening, the question on most people's minds was not whether Cantor would lose to Brat, but whether Brat could send a message by just narrowing Cantor's margin of victory enough for anyone to notice. He did that, and then some. 

Now, conservatives who hoped that a strong turnout for Brat would push back at the national effort to reform immigration in the U.S. are pretty sure they've just killed that effort in its tracks with tonight's result: 

It looks like Cantor's options for seeking re-election are limited by Virginia law. Essentially, he'd have to run as a write-in candidate, as he can't even get his name on the ballot as an independent in the state. The second-ranking House Republican has been in Congress since 2001. As Politico points out, Cantor was the presumptive successor to the Speakership whenever Speaker John Boehner decides to retire. 

Here's Cantor's concession speech: 

Brat, an economics professor at Randolph-Macon College, will face off in November against Democrat Jack Trammell who as it turns out is also a professor at Randolph-Macon College. Which means we already have some polling numbers to share (OK not really).

In other primaries news, Sen. Lindsey Graham, i.e. the guy everyone thought actually could be in trouble today, handily won his primary in South Carolina. 

This post on a developing story has been updated.