For the third consecutive week, Republican gubernatorial candidate and state Senate President David Williams has unveiled an advertisement in the GOP primary.The new 60-second radio spot mixes parts of previous ads while focusing on improving the state's economic troubles. It says that if elected Williams will create jobs and fight to reduce size of state government.The ad doesn't mention Williams's two primary opponents or Democratic Governor Steve Beshear, but it does take aim at President Barack Obama, saying he will stand up to the president to protect coal.It's an easy target, considering Mr. Obama's approval rating in the commonwealth is 38 percent.Check it out:Williams is running against Jefferson County Clerk Bobbie Holsclaw and Louisville businessman Phil Moffett, who is a Tea Party-backed candidate in the May 17 primary.So far, neither of Williams's opponent have run an advertisement.