Washington (CNN) - Florida Gov. Charlie Crist, trailing in the Florida Republican Senate primary against Marco Rubio, debuted his first television ad of the campaign.
Not surprisingly, it's a negative one.
Hoping to tarnish Marco Rubio's image as a fiscally conservative warrior, Crist uses the ad to go right after his GOP rival over a series of unflattering news reports detailing Rubio's questionable spending habits while he served in the Florida state House.
"We thought he was different," an ominous-sounding female voice narrates in the 30-second commercial. "Ideologically pure. Marco Rubio shot to national stardom. Called 'The Republican Obama.' Now, comes the truth."
"Rubio used Republican political donations on his lavish lifestyle," the narrator continues. "Then, failed to properly disclose it, violating the law. Marco Rubio, how disappointing."
Crist's campaign called the ad buy "significant," but would not reveal more details about its television strategy.
The ad is likely the first of many negative commercials from the Crist campaign, which has a sizeable cash advantage over the front-running Rubio. To win the nomination, Crist needs to raise doubts about Rubio's conservative bona fides among the loyal Republican voters likely to participate in the August primary.
Rubio's team shot back, labeling Crist "a liberal Republican" who is running "a campaign of smears and distortions."
"Instead of addressing the big issues facing Floridians, Charlie Crist has shredded his last bit of credibility with a negative ad filled with false attacks," said Rubio spokesman Alex Burgos. "In fact, Charlie Crist has spent more time lately attacking Marco Rubio than he has fighting Barack Obama's agenda. No wonder there is so much talk about him leaving the Republican Party."
The winner of the primary will face Democrat Kendrick Meek in the general election.