Specifically, Biden said Romney wanted to get rid of regulations on some of the country's largest banks, which would essentially put voters "back in chains."

"They’ve said it. Every Republican’s voted for it. Look at what they value and look at their budget and what they’re proposing. Romney wants to let the — he said in the first 100 days, he’s going to let the big banks once again write their own rules, unchain Wall Street," Biden said Tuesday. "They’re going to put y’all back in chains."

A number of top Republicans quickly pounced on the remarks. Republican National Committee Chairman Reince Priebus called the comments "shameful."

"I think it takes things to a new level, a level of negativity, and I think it was a shameful comment," Priebus said Wednesday.

Biden later on Tuesday said he misspoke and that he intended to use the word "unshackle."