In one of the most stunning primary election upsets in congressional history, the House majority leader, Eric Cantor, was soundly defeated on Tuesday by a Tea Party-backed economics professor who had hammered him for being insufficiently conservative.
The result delivered a major jolt to the Republican Party — Mr. Cantor had widely been considered the top candidate to succeed Speaker John A. Boehner — and it has the potential to change both the debate in Washington on immigration and, possibly, the midterm elections.