College professor David Brat knocked off House Majority Leader Eric Cantor (R., Va.) Tuesday in the biggest congressional upset in years.

Mr. Brat ran an underfunded campaign based in part on Mr. Cantor’s supposed support for comprehensive immigration reform, when Mr. Cantor has for months been seen by immigration reform advocates as the key roadblock to House legislation.

Mr. Brat was so unknown that his Wikipedia entry was only two sentences before Tuesday night.

Mr. Brat, an economics professor at Randolph-Macon College in Ashland, Va., had support from radio host Laura Ingraham, who hosted a rally with him in a Richmond suburb last week that centered upon Mr. Brat’s opposition to immigration reform.