It didn't take long for Santino to start dominating races. "He got very good very, very fast," Mike says. In the region, "he was beating kids who were 12 and 13 when he was 7." Since then, well, you could get lost in the kid's accumulated accomplishments over the various circuits in which he competes, but suffice it to say he has dominated every level, setting benchmark after benchmark along the way.

His professional role model (which is different from an idol) is Lewis Hamilton, the 25-year-old British driver who won the 2008 Formula One championship. Hamilton is a bone fide sensation, in part because he is black (in a sport that's whiter than golf ) and in part because he wins so often. Hamilton, like most of his Formula One peers, learned to drive in a go-kart. He started at 8 and won his first national race when he was 10.

"I beat his record," Santino told me. "I won my first at 8. So I kicked his butt."

One afternoon, I was hanging around the family track while Santino was breaking in a new kart. The compound was originally an old Mafia hangout; viewed from overhead, the track is in the shape of a handgun. ("I haven't dredged the pond," Mike jokes.)

This new kart weighs 262 pounds. That's much bigger and heavier than what Santino's used to, and he needs to get accustomed to the physicality of pushing it around the track. (Currently, he weighs sixty pounds and needs pedal blocks to reach the brake and accelerator with his size 3 feet.) Having taken some laps myself, I can tell you that even for a 180-pound man, steering a race-quality go-kart is very physical; my arms were sore for a full day afterward. Santino's got a new fitness program—some running, some pull-ups, some Little League, all of it fueled by chocolate PowerBars and Frosted Flakes.

He pulls into the pit, climbs out, and shakes his arms like they're wet.

Mike asks how the car felt, and Santino mumbles unintelligibly. He is impossible to understand when his helmet is on. ("That's because I chew on my head sock," he explains later. "Write that down.") He pulls off the helmet and head sock to reveal red splotches where he scrubbed off the temporary butterfly tattoo his younger sister had applied the previous night.

"How close are we to this go-kart being good?" his dad asks.

Santino holds his finger and thumb an inch apart.

"What's the problem?"

"It's hard to steer. It has a lot of transfer, but it doesn't have as much grip as my other kart. I like the harder chassis. But this definitely has more feel."

I am not omitting "ums" and "uhs" and "wells." When it is time to talk racing, Santino may as well be his father's age.

It's a chilly March Saturday, and Santino Ferrucci finds himself in Ocala, Florida, home to the final race of the Florida Winter Tour (FWT). This is the opening series of the national go-kart racing season, and thus a magnet for top drivers across the age spectrum.

The whole Ferrucci family has come from their home in Woodbury, Connecticut: Mike and Val, Santino's parents, as well as his younger sister, Alessandra, also small, also spunky, also spectacularly coiffed. It's not typical for all four to attend a race—Alessandra thinks they're boring; she'd rather be riding horses—but this is a special weekend. Her brother could become the first person ever to win back-to-back FWT titles in the same class.

In this case, that class is cadet, for kids up to 13. He won in 2008, when he was 9. Now, with three years of eligibility remaining, a repeat is all but certain. He doesn't even need to win this race, necessarily; he just needs to avoid catastrophe and to not cede too much ground to the only kid with a (faint) statistical chance of catching him: Jimmy Cabrera, a 9-year-old from the Dominican Republic whose black suit and tinted visor conveniently fates him into the role of villain.