In a historic primary upset in Virginia on Tuesday, House Majority Leader and Republican Congressman Eric Cantor, was defeated by his Tea Party-backed challenger Dave Brat.

The defeat is being treated as a shocking political development by national media outlets and pundits, as few thought it possible that Cantor—one of the most powerful GOP leaders in Washington—was under serious threat from Brat, a college professor who ran as “the true conservative” to the right of the Majority Leader as he took a specifically hardline and regressive stance on immigration.

Though Cantor raised a reported $5.4 million compared to Brat’s $200,000 and outspent him 20-to-1, his challenger was ahead by a margin of 56 to 44 percent when Cantor conceded the race just before 8:30 PM.

According to Politico:

As the Huffington Post notes, no sitting House Majority Leader has lost an election since 1899.