A political action committee supporting Republican presidential candidate Mitt Romney will spend $464,000 on television advertising in Maryland, the first instance of a major third-party television buy in the state and the first ads supporting any candidate in the race for the GOP nomination.Restore Our Future PAC spokeswoman Brittany Gross said the ad will appear statewide in Maryland. The ad, titled "Values," has run in other states and criticizes former Pennsylvania Sen. Rick Santorum for his voting record in Congress, including to raise the nation's debt ceiling. "More than 20 years in Washington changed Santorum's values," the ad's narrator says. The ad buy comes on the same day that Romney will visit Maryland for a town hall forum at an American Legion Post in Arbutus. It underscores that Romney is making a play for the state's 37 delegates, even as Santorum and the other GOP candidates have not campaigned in the state for many months.Restore Our Future spent $10.1 million on television, $775,000 on internet ads and $523,000 on direct mail last month, according to a Bloomberg analysis of Federal Election Commission reports. The spending has allowed Romney's campaign, which is technically separate from the PAC, to dominate airwaves in key states.