Today, an eight-year speaker of the North Carolina House of Representatives, Jim Black, will plead guilty to federal corruption charges and receive a prison sentence. It’s the latest in a series of guilty pleas related to a criminal conspiracy of lobbyists and public officials involving pay-for-play bribery deals, violations of lobbying and campaign-finance laws, regulation of the video poker industry, passage of a state-run lottery, and a general seediness in North Carolina state government. And other state lawmakers may yet be caught in the dragnet. Black, a Democrat and optometrist, had used his fundraising prowess and bare-knuckle tactics to maintain...