"When you're dealing with an incumbent president like Obama, there are generally in my opinion two boxes people in America have to check: Did this president fulfill the mission? Did he meet the promises and are we better off today than we were three or four years ago? That's the first question and that's the first box," Priebus said on MSNBC's "Daily Rundown" Tuesday.
Priebus said the story of the presumptive Republican nominee is one of a "good, decent man" that built a successful business, managed the Olympics and governed Massachusetts.
"That story is a story of success that we in the Republican Party are going to celebrate. We're going to celebrate the American Dream and success. We're not going to be on defense on success, and I think that is something that you're going to see at the convention," he said.
The RNC chairman also explained his recent charge that President Obama has "blood" on his hands when it comes to Medicare funding.
On Sunday, Priebus told NBC's "Meet the Press" that "if any person in this entire debate has blood on their hands in regard to Medicare, it’s Barack Obama. He’s the one that’s destroying Medicare." Priebus said that's because Obama "didn’t cut Medicare, he stole $700 billion from Medicare to fund ObamaCare."
Priebus repeated the claim on MSNBC that Obama "stole" $700 billion from Medicare to put towards his signature healthcare legislation.
"What Mitt Romney has done is he, in his plan, he's decided that he's going to put that money back into Medicare. I think [GOP vice presidential candidate] Paul [Ryan]'s plan is a little different ... this is about what we're going to do about something that both Democrats and Republicans agree with," he said.