Romney, meanwhile, had high praises for former president George W. Bush, who has been relatively quiet since stepping out of office, unlike Cheney, who has emerged as a leading critic of the Obama administration. Romney today argued that history will judge Bush kinder than he is portrayed now.
"When it comes to pinning blame, pin the tail on the donkeys [Democrats]," Romney said.
Rubio was undoubtedly the star of the day. The 39-year old son of Cuban immigrants is locked in a tight battle for the GOP nomination for the U.S. Senate seat in Florida. Gov. Charlie Crist, who has much of the official Republican Party establishment support, has been running slightly behind Rubio in recent polls there.
Rubio, as expected, delivered a speech charged with anti-Obama administration rhetoric as he kicked off the convention. The former Florida state House speaker and tea party movement supporter panned Obama on all fronts, from health care to energy legislation to national security.
"From the tea parties to the election in Massachusetts, we are witnessing the greatest single pushback in American history," Rubio declared.
"2010 is not just a choice between Republicans and Democrats. It's not just a choice between liberals and conservatives. 2010 is a referendum on the very identity of our nation," he added as he portrayed Obama's policies, without mentioning by him name, of that like a socialist country like the one his parents fled.
ABC News' Claire Shipman, Z. Byron Wolf and David Chalian contributed to this report.