Spencer Pratt is the underdog in the Los Angeles mayoral race, but he's starting to scare Mayor Karen Bass and national Democrats.

Spencer Pratt is the underdog in the Los Angeles mayoral race, but he's starting to scare Mayor Karen Bass and national Democrats.

The city's Democratic establishment loathes him. But his insurgent campaign has captured the hearts (and wallets) of a surprising number of Hollywood heavyweights to become a…