Congressman Eric Swalwell is running for president, and a country and even his own home state are asking: Who is this guy? And why on earth is he running?

The answer lies in California’s perverse top two election system.

Swalwell is a creature of top two, which makes him the first presidential candidate from the land of top two.

Swalwell launched his political career back in 2012, by making the sort of Democrat-on-Democrat challenge to incumbent Pete Stark, that top two is designed to produce.  

So why is Swalwell running, without any constituency clamoring for him, or knowing who he is? Because in a top two system, you don’t need a constituency. Top two’s first round—yes, I know the ignoramuses in state government and the media call it a primary, but they’re wrong—is all about figuring out a way to get yourself through a very crowded field of contenders, even when no one knows who you are.

That’s the exact challenge Swalwell faces in the presidential election. So why not take a shot? In a field this large—18 candidates and counting, a number not atypical in top two first round in California—strange things happen, and unknowns can emerge.

In defeating Stark, Swalwell emphasized the volatility and age of the incumbent—personal attacks are essential in top two system. Swalwell also ran aggressively both to Stark’s left and to the middle. Top-two doesn’t actually favor moderates—it favors loud voices that drive small passionate groups of people to the polls. The goal is to finish in second place in the first round, and then bloody the other guy in the runoff.

Swalwell just has to find his passionate fans, maybe among those who can stand cable news and his endless appearances on cable news. Actual accomplishments—which Stark had but which Swalwell doesn’t—don’t matter much in the world of top two. Or of presidential politics.