But Giannetti canceled the plan to import the machines just hours before last night's event, fearful of a public relations blunder.
Giannetti said he had state police permission to install the machines in a demonstration, and a company agreed to bring them from Delaware.
But the hint of conflict was unavoidable. Maryland lawmakers remain embroiled in a debate over legalizing slot machines. Also, the track is the location of a meeting between De Francis and Miller that resulted in $225,000 in donations by the track owner to a national legislative campaign fund that Miller controls. Laurel Park's owners, Magna Entertainment Corp. and De Francis, could benefit richly from slot machines.
That donation is the subject of an FBI investigation.
In a speech to a crowd of 200, Giannetti joked about the attention his fund-raiser has received.
"I want to thank the Gazette, The Washington Post and The Baltimore Sun for bringing the FBI. You know what people are saying about this fund-raiser," he said. "You have Mike Miller, [Prince George's County Executive] Jack Johnson at the racetrack. Watch what you say in the restroom."
Miller and Johnson were the featured guests at the fund-raiser.
Giannetti received a $4,000 donation last year from the Democratic Legislative Campaign Committee that Miller heads.
Miller and De Francis, who also attended the event, denied knowledge of the planned slot machine demonstration.
"I don't know anything about it," the Senate president said.
De Francis said he was happy to make a donation to Giannetti's re-election bid.
"He's a very strong supporter of the track," De Francis said. "I dare say we might be the largest private employer in his district."
Giannetti voted for a bill this year to legalize slot machines at Laurel and three other racetracks, but the plan died in the House of Delegates. "I think it would be great for the economic development of this area," Giannetti said.
The senator said he sold about 225 tickets to the event, raising about $50,000. Ticket prices were $1,000, $500, $250 and $100, he said. He collected nearly $80,000 for his Senate race last year when he defeated incumbent Arthur Dorman.