Something is wrong with the American Left. The recent spate of violent protests on college campuses has been well-documented, but the violence and intolerance championed by left-wing student activists is beginning to creep off campus and into mainstream public life.

The reason for this is straightforward enough: although progressives pride themselves on their putative tolerance and diversity, the imperatives of leftist politics are fundamentally illiberal. Justice imposed through power is the philosophical foundation of the political left, and when earnest progressives become convinced the only avenue to power is violence, their tolerance quickly falls by the wayside. Consider a few recent events, none of which involved college protesters but all of which were marked by threats of violence.

Ahead of a town hall meeting this week in Virginia’s fifth congressional district, Republican Rep. Tom Garrett received a series of disturbing threats—not just against him but also his wife and family, even his dog. One message said bluntly, “This is how we’re going to kill your wife.”

As a result, the town hall event was heavily guarded, with uniformed and plain-clothes security lining the walls and scattered throughout the 300-seat room.

Earlier this month, Jennifer Carnahan, the new chairwoman of the Minnesota Republican Party, received a torrent of racist hate mail and at least one threat of physical violence that forced her from her home for a weekend. Carnahan, who is Korean-American, was targeted after publically apologizing and calling for the resignation of those responsible for an offensive image posted to the 7th Congressional District Republicans Facebook page.