Yes, but only because at this current time the Federal Government is preventing individual states who would ban abortion from doing so. So removing that obstacle would allow at least some states to ban it, to me it seems a viable first step.
Even the abolitionists in the 19th century first tried to prevent slavery in only certain states, even though in principle the would be against it in every state. Sometime you have to achieve the goal on step at a time.
Again, you’re not stating the Paul position accurately. They don’t say that it needs to be done “step by step.” They say that this is the “prerogative of the States.”