The Florida Democratic Party's first TV spot of the 2014 governor's race airs this week and attacks Gov. Rick Scott over an old weakness: Medicare fraud."Maybe you've heard about what was the largest Medicare fraud in history, committed when Rick Scott was a CEO," says the ad. "Or that Scott's company paid record fraud fines of $1.7 billion."The commercial is similar to those that appeared in the 2010 election when Scott's Republican rival, Bill McCollum, and then his Democratic opponent, Alex Sink, wanted to ensure that voters knew about the 1997 fine paid by Columbia/HCA, a hospital company Scott built.The Democrats' ad, announced during the week statewide candidates qualify for office, serves as a campaign milestone as well as an indication of the negativity in store for Floridians through November."Charlie Crist doesn't have a record to run on,'' Scott said Tuesday when asked if the ad meant he needed to explain to voters what happened at Columbia/HCA."While he was governor, we lost 800,000 jobs. He left me with a $3.6 billion budget deficit. So, this is what he's going to do. He's a professional politician. He's a mudslinger.''Scott has spent more than $13 million on TV already, about half dedicated to bashing Crist.The Democrats' ad buy isn't immediately clear. A statewide ad buy usually has to be $1 million a week to take effect. Democrats say they'll ramp up to spend more in the coming weeks.This spot is set to air in the three media markets where Scott has spent the most: Tampa Bay, Orlando and West Palm Beach.The Miami-Fort Lauderdale media market is too expensive and too Democratic for Democrats to advertise there now. But the fact that they're going up in Tampa Bay, Crist's home base, indicates that Scott's spending has paid off and they need to try to keep the incumbent polling below 45 percent.Ever since Scott took office in 2011, his poll numbers have been poor for an incumbent presiding over an improving economy. It's partly a legacy of the Medicare-fraud story that Scott's opponents burned into the mind of the electorate.In 2010, Scott got fewer votes than the five other statewide office holders — all Republicans — including Sen. Marco Rubio, who fought a de facto three-way race with Crist (then a struggling independent) and Democratic Miami congressman Kendrick Meek.The Democrats' commercial is named "Answers" — a reminder of how few of them are directly given by Scott.The ad mentions how Scott pleaded his Fifth Amendment right against self-incrimination amid the federal investigation of Columbia/HCA. In the commercial, the video footage of a young Scott testifying comes from yet another deposition in another lawsuit, involving Central Florida hospitals. Times staff writer Steve Bousquet contributed.