Sure, but arguably the lawsuit is deficient in that it targets the wrong defendant. This is basically making a class action from a number of disparate claims that involve the state legislature (which approved the state electoral law and empowered election officials), the governor, which certified the vote, the certified slate of electors, etc.
There was nothing stopping Texas from suing earlier in state court about the uncons utionality of the law under the same pretenses it's suing now. But they didn't.