As Newt Gingrich and Mitt Romney prepare to take center stage Saturday in the ABC News Iowa presidential debate, Democrats are honing a new line of attack against Gingrich's leadership while intensifying their months-long offensive against Romney's character.

The move - coming through a series of Web videos, press conferences, and television interviews - signals an attempt by supporters of President Obama to aggressively define his two most likely challengers and, in doing so, fan the flames of an internal GOP debate.

"The Republican Party has split into two parties: the tea party and the martini party," chief Obama campaign strategist David Axelrod told Bloomberg this week, offering his spin on the Gingrich-Romney divide. Axelrod said the dynamic could mean a protracted primary fight, which many say could be advantageous to Obama.

Earlier this week, Axelrod launched the first direct Democratic attacks on Gingrich, labeling him the "godfather of gridlock" for his role in the federal government shutdown of 1995 and the partisan battle to impeach President Bill Clinton.

"He really has been the champion of gridlock," Democratic National Committee chairwoman Debbie Wasserman Schultz repeated Thursday. "He made sure polarization was the name of the game here in Washington." (Schultz did not mention, however, that there were notable bipartisan legislative achievements under Gingrich's tenure in the House.)

The DNC also opened a new chapter in its playbook against Romney with a political memo and Web video - "Mitt Romney Through the Ages" - chronicling the former Massachusetts governor's shifting policy positions and concluding that he suffers from "multiple political personality disorder."

Still, as the Democratic messaging machine pursues Gingrich and Romney separately, strategists from the Obama campaign to the White House are continuing to paint all Republicans on the campaign trail and in the halls of Congress as cut from the same cloth.

"Neither of the frontrunners really understands the needs of the middle class," said a senior Democratic strategist in characterizing how the party was preparing to bracket the ABC Iowa debate.

"Romney got rich at Bain by laying off middle class American workers and shipping jobs overseas, and Gingrich is sort of the $60,000-a-speech influence peddler. He didn't have to be a lobbyist because he was making so much money," the strategist said.

"They are doing and saying whatever they can to win over the tea party vote, but they have both come from this 'martini lifestyle' where they don't understand the problems of middle-class Americans and aren't offering policies that respond to them."

A spokeswoman for Romney has called the focus on his campaign by Democrats an effort to distract voters from Obama's economic record, and a sign that Romney is considered the most formidable threat.

Three new Quinnipiac polls in the battleground states of Florida, Ohio and Pennsylvania show Romney and Obama neck-and-neck in a hypothetical 2012 match-up, with Romney holding a slight edge in Florida and Pennsylvania.

But Gingrich isn't far behind.  In the latest ABC News/Washington Post poll of Iowa caucus goers, the former speaker of the House scores evenly with Romney as the best candidate to beat Barack Obama.

In the Quinnipiac Ohio poll, Gingrich holds a narrow edge over Obama, while in Florida and Pennsylvania he trails but stands within two points and eight points, respectively.

"I'm going to stay positive, I'm going to talk about how we solve the country's problems. And I have one opponent: Barack Obama," Gingrich said Thursday when asked about attacks from his GOP rivals and Democrats.