Vice President Biden said Tuesday that the middle class has been “buried” during the past four years, prompting a rare moment of concord with Republican Mitt Romney’s campaign.

“Agree with @joebiden, the middle class has been buried the last 4 years, which is why we need a change in November,” Romney said on Twitter.

“We agree!” his running mate, Rep. Paul Ryan (Wis.), told a crowd in Iowa. “That means we need to stop digging by electing Mitt Romney as the next president of the United States.”

Biden, speaking at a campaign event in North Carolina, said that Romney would raise taxes on the middle class. “How they can justify . . . raising taxes on the middle class that has been buried the last four years?” he asked.

At a later event, Biden elaborated: “The middle class was buried by the policies that Romney and Ryan have supported.”

The Romney campaign obviously sees the remark as a potential stumble for President Obama, who has maintained a slight edge in the polls during the past two weeks.

Romney surrogate John Sununu, in a conference call with reporters, was asked if he thought the vice president’s words would move poll numbers. The former New Hampshire governor replied, “No, but I think it sets the stage for the debate that will take place tomorrow.”

The comment “tells the public this is what you really ought to be looking for” in the debate, Sununu added.

Elsewhere, Romney, who has come out against Obama’s executive order deferring deportation for some young illegal immigrants, said in an interview that he would not deport those who have received temporary visas.

“The people who have received the special visa that the president has put in place, which is a two-year visa, should expect that the visa would continue to be valid. I’m not going to take something that they’ve purchased,” Romney told The Denver Post. “Before those visas have expired, we will have the full immigration reform plan that I’ve proposed.”

Romney has repeatedly said that his plan isn’t to “round people up” and “deport people.”