AUSTIN, Texas (AP) — If Texas is going to be competitive in 2020, the first race wasn't.

Democrats went all-in on a legislative runoff in the booming Houston suburbs, drumming up endorsements from Joe Biden and Elizabeth Warren and putting $1 million on the ground. Still, a Republican real estate developer who had lost seven previous tries for office cruised to a double-digit victory.

It was a high-profile defeat for Democrats who supercharged a sleepy statehouse special election in a bid to make an early 2020 strike on the GOP's biggest turf. On Wednesday, Republicans called it a lesson.

"The...