The Republican presidential candidate with the line of credit at Tiffany’s is making fun of the candidate with the Swiss bank account. The one who got wealthy working the inside Washington game is whaling away at the one who got wealthy working the angles of high finance. The economic diversity at the top of the Republican field runs the gamut from A to B.

In the 2010 election, Florida was the epicenter of the struggle in the Republican Party between insiders and outsiders. Tea Party insurgent Marco Rubio won a Senate seat by trouncing establishment candidate Charlie Crist. But despite the outsider movement that briefly emboldened the Rick Perry and Herman Cain candidacies, the Republican primary has come down to a battle between two insiders. Whether Mitt Romney or Newt Gingrich wins the Florida primary on Jan. 31, it will be a triumph for men who have profited from knowing how to work the system.

All politicians who run for president have some sort of insider connection. Barack Obama owns a house that is the product of a cozy deal with convicted Chicago real estate mogul Tony Rezko. He has stocked his administration with Wall Street insiders. The public has grown increasingly suspicious about any kind of insider taint, believing that those with favored positions both fail to see what is wrong in Washington and on Wall Street, and unfairly benefited from bailouts.

Newt Gingrich has as much of this insider taint as he does personal taint. He was a longtime politician. Bad. He traded on that political experience to make money helping companies work the system. Bad. One of the companies was Freddie Mac, a villain for Tea Party Republicans in the 2008 economic collapse. Bad. It’s no surprise that Mitt Romney has been hammering Gingrich on this front since the campaign moved to Florida.

Mitt Romney’s career in private equity: Also bad. It makes him vulnerable to the charge that he is a part of the system that led to the economic collapse. Disclosure of his tax returns also highlights his insider status. He can afford to work the system to his advantage through tax avoidance in a way that very few ordinary Americans can.

The Gingrich campaign circulated an article this week arguing that Romney’s insider status meant he’d never be able to go after the troubled banks that caused so much economic distress. On Thursday, Gingrich made that attack himself:

Let’s be clear, you’re watching ads paid for with the money taken from the people of Florida by companies like Goldman Sachs, recycled back into ads to try to stop you from having a choice in this election. … What level of gall does it take to think that we collectively are so stupid that somebody who owns lots of stock in Fannie and Freddie Mac, somebody who owns lots of stock in Goldman Sachs, who is insistently foreclosing on Floridians, who is surrounded by lobbyists who are already protecting Fannie Mae and Freddie Mac, can then build his entire negative campaign in Florida around a series of ads that are just plain false?

Yet neither candidate thinks his own insider status is a problem. Indeed, they’re each running on it. They just call it “experience.” Gingrich argues that his time in Washington gives him special insight how to turn his grand promises into effective action. Romney argues that even his failures in the business world help him understand how to turn around the economy.

Why is Gingrich getting the better of this insider battle at the moment? Appearing to be an outsider is more important than actually being one. Newt Gingrich is vastly better at this than Romney. There is nothing conventional or establishment about the Gingrich campaign. It’s messy and rugged and risky. Gingrich consistently trounces his opposition among Tea Party voters in polls and exit polls.

Gingrich is also helped by attacks on him by establishment figures: John McCain, Trent Lott, and a parade of former and current officials who populate the daily Romney campaign conference calls savaging Gingrich. Thursday afternoon, even Bob Dole took a swing at Gingrich. Dole is like many in Washington who grumble about Gingrich, can’t believe he’s doing so well, and don’t want him to be president, but had assumed he’d collapse from his own hubris. “I have not been critical of Newt Gingrich, but it is now time to take a stand before it is too late. If Gingrich is the nominee it will have an adverse impact on Republican candidates running for county, state, and federal offices. Hardly anyone who served with Newt in Congress has endorsed him and that fact speaks for itself. He was a one-man-band who rarely took advice. It was his way or the highway.”

Bob Dole was the Mitt Romney of his day, an establishment figure the grassroots didn’t like much. Same with John McCain. George H.W. Bush dislikes Gingrich intensely and has unofficially endorsed Mitt Romney. If Gingrich is really lucky, Bush will make his endorsement official.