Democrats used a tribute video to the late Sen. Edward Kennedy (D-Mass.) to show the deceased senator criticizing Mitt Romney during their 1994 Senate race.
The tribute included clips from a debate Kennedy had with then-Senate candidate Romney.
The clips showed Romney saying he supported abortion rights and had a universal healthcare plan. Kennedy responded by saying Romney had switched his opinion many times to become more liberal.
The seven-minute tribute video featured about a minute of edited clips from the debate. In those selections, Kennedy is shown getting the upper hand on Romney.
Kennedy is also shown at a campaign rally telling supporters about Romney, "Now he's for family leave, now it looks like he's for a minimum wage, now he's for education reform, and if we give him two more weeks he may even vote for me."
Kennedy defeated Romney in that race, which the video notes.
The crowd in the Time Warner Cable Arena cheered loudly for the beginning of the Kennedy video tribute, but when the video turned to Kennedy's debates with Romney, the arena erupted in the biggest applause of the night. When the video concluded, chants of "Teddy! Teddy!" rang out.
Republican National Committee Chairman Reince Priebus complained about the move on Twitter: "Classless Dems use tribute video of deceased Ted Kennedy to attack Mitt Romney," he wrote.
Rep. Edward Markey (D-Mass.) called the video "fantastic" and "powerful."
"Of course, most of the people here [at the convention] were inspired by either John or Robert or Teddy to get into politics. So that's an emotional moment for just about any Democrat," he said. "Everybody who believes in the democratic body was inspired by the Kennedy family. And I'm one of them."
And Rep. Gerry Connolly (D-Va.), asked about Republican criticism of the video, said: "I guess I'm pausing at the unbelievable chutzpah of Republicans calling anything going too far. Really. You mean they have some standards?"
Terry McAuliffe, the former chairman of the Democratic National Committee, said Democrats were understandably proud of Kennedy's accomplishments.
"Giving a tribute to Sen. Kennedy and talking about the issues that mattered to him, I think, was entirely appropriate," McAuliffe said.
Kennedy's nephew Joe Kennedy III, who is running for Congress in Massachusetts, introduced the video, which featured a long list of Sen. Kennedy’s legislative accomplishments.
“Make no mistake, he is here with us this evening,” Joe Kennedy III said.
— Amie Parnes, Julian Pecquet, Bernie Becker, Ben Geman and Russell Berman contributed.
— This story was last updated at 10:35 p.m.