Seven GOP presidential rivals tangled Wednesday night on a Simi Valley, Calif., stage, arguing over who is the best to take on President Biden next fall. It was a rambunctious night filled with personal attacks by candidates battling for survival, culminating in a clash over curtains between Sen. Tim Scott (R-S.C.) and his state’s former Gov. Nikki Haley. None of the contenders are within spitting distance in polls to former President Trump, who for a second time didn’t bother showing up for the debate. That added to the sense of desperation for some of the would-be contenders, who know the...