Updated

Want a peek inside the Democratic playbook as the presidential race shifts fully into general election mode? Just listen to Vice President Joe Biden.

In the past few weeks, he has branded presumptive GOP nominee Mitt Romney "consistently wrong," "uninformed" on foreign policy, someone aiming to "end Medicare as we know it" and an advocate of the wealthy at the expense of the middle class.

President Barack Obama largely avoids direct engagement for now; on Tuesday he referred to a candidate "who shall not be named." But Biden is diving into the No. 2's traditional attack-dog role -- earlier and more aggressively than usual, some say -- with comments designed to singe Romney.

It's not just a casual remark here and there. Most Biden speeches lately contain a fresh poke at Romney, and he's fired up a Twitter account, too. Taken together, the lines showcase how the incumbent administration intends to frame the campaign against an opponent who has just about locked up his party's nomination.

"Mitt Romney has been remarkably consistent as an investor, a businessman, as governor of Massachusetts, and now as a candidate for president. Remarkably consistent. Consistently wrong," Biden said last month in Florida.

A week later at a manufacturing plant in Iowa, he held Romney out as a protector of corporate profits above all else. "Look," Biden said, "Gov. Romney's business practices and his policies have clearly benefited the wealthy and most powerful among us, often at the expense of working and middle-class families."

Where Biden is making the remarks is just as telling. He's spent time in probable November battlegrounds: Florida, Iowa, Ohio and Wisconsin. He heads Thursday to New Hampshire after squeezing in a Minnesota fundraiser Wednesday for Democratic Sen. Amy Klobuchar, during which he argued Republicans are coming off as too strident for their own good.

"They are saying exactly what they believe," Biden said. "As my mother would say, God bless them."

In New Hampshire, Biden will continue the administration's promotion of the "Buffett rule," named for billionaire investor Warren Buffett. It argues that wealthy taxpayers should not pay taxes at a lower rate than middle-class wage-earners.

In an excerpt released early Thursday by the Obama campaign, Biden says, "The Romney Rule says the very wealthy should keep the tax cuts and loopholes they have, and get an additional, new tax cut every year that is worth more than what the average middle-class family makes in an entire year."

The Romney campaign hasn't let Biden's critiques go unchecked, pushing back at specific statements and dredging up past Biden comments that cast Obama in a poor light. Ahead of Biden's trip to New Hampshire, former Gov. John Sununu issued a tongue-in-cheek welcome on behalf of Romney's campaign.

"I don't agree with much of what Joe Biden says, but I completely agreed with him in 2007 when he said Barack Obama wasn't ready to be president. That was true then, and is still true today," Sununu said. "I welcome the vice president to New Hampshire, and I hope he continues to visit our state -- because it gives us a very visible opportunity to talk about the failures of this administration."

Ticket mates are typically expected to land the toughest blows in presidential politics. It lets the presidential nominee remain above the fray and focused on loftier goals and grand themes of their campaigns.

Biden had 36 years of Senate experience -- and two stunted presidential campaigns of his own -- when Obama selected him in 2008. He was seen as the seasoned hand to the relative newcomer Obama and a plain-spoken campaigner who could connect to blue-collar voters.

"We saw this four years ago, Joe Biden playing off Barack Obama's more cerebral, professorial, contemplative style," said University of Missouri professor Mitchell McKinney, a scholar of political rhetoric and presidential debates. "Biden has had that persona of shoot-from-the-lip and take-it-to-them sort of style."

Biden mocked Republican presidential nominee John McCain for blanking on how many houses he owned and disputed the Arizona senator's ability to live up to his maverick reputation after tacking right in the race. "I know Halloween is coming, I know Halloween," he said late in the race. "But John McCain dressed up as an agent of change? That costume just doesn't fit, folks."

That year, GOP vice presidential pick Sarah Palin loved to zing Obama's past as a community organizer and contrast him with her running mate, who was a war hero.

"This is a man who can give an entire speech about the wars America is fighting and never use the word `victory,' except when he's talking about his own campaign," Palin, then the Alaska governor, said in her national convention speech.

But at this stage of this campaign, Biden has no peer who can easily command attention and speak with the full weight of the campaign. Romney, who still lacks the needed delegates to rightfully call himself the GOP nominee, is probably months away from picking his own running mate.

President George W. Bush enjoyed a similar two-on-one advantage for many months of his second-term bid in 2004, with Vice President Dick Cheney at his disposal. Cheney publicly doubted Democratic nominee John Kerry's resolve on national defense, but the vice president didn't play a sustained role in criticizing the rival nominee this early on.

"If you go back and read a lot of the speeches, you will not find (Kerry's) name very much," said Sara Taylor Fagen, a Republican strategist and White House political adviser in Bush's administration. "It's a little surprising that they've gone so hard so fast. To some degree, you want to keep the president and the vice president elevated as long as possible."