Dear GM: Don’t revive Hummer. Focus on Cadillac instead.

Please, General Motors, don’t revive Hummer.

The brand is toxic, and the idea that adding a brand can cure what ails your existing business — which, in case you’ve forgotten, is selling Cadillacs, Chevrolets, Buicks and GMCs — makes no more sense today that it did when the automaker tried it with Hummer, Saturn and Saab.

During its lost decades of the 1980s and ’90s, GM wasted billions of dollars and the talent of countless engineers and designers chasing the fantasy of those three brands. They’re gone, and GM is better off without them, able to concentrate on providing strong lineups for fewer brands.