President Obama’s reelection campaign is out with a new ad in Ohio, Iowa and Virginia today that bashes former Massachusetts governor Mitt Romney for shipping jobs overseas and for — you guessed it! — having a Swiss bank account.

The new ad is the third of the Obama reelection effort. He began his advertising campaign in January with a commercial touting the Administration’s successes on energy and ethics while slamming Americans for Prosperity. His second hit Romney for supporting “big oil”.

The three ads are a mix of positive messaging for Obama on energy and ethics with each in the series tilting progressively more toward attacking Romney and less toward touting the president’s record.

And, if history is any guide, the Obama campaign will dish up a steady diet of negative ads from here on out.

Remember that in his 2004 reelection campaign, President George W. Bush ran an initial slate of positive ads touting his work to keep the country safe after the Sept. 11, 2001 terrorist attacks before quickly moving into a full-scale assault on the record (and personality) of Massachusetts Sen. John Kerry. (Even Bush’s positive ads were controversial, with many Democrats insisting he was politicizing the terrorist attacks.)

Why? Because Bush whose popularity was sliding amid rising questions about the war in Iraq — among other things — knew that there was no path to victory against Kerry by spending any substantial time touting his accomplishments during his first four years in office.

Partisans on both sides were already lined up either for or against Bush and no amount of positive (or negative) advertising would move them off of how they intended to vote. Undecided voters didn’t like Bush so positive ads amounted to a waste of time. The only way to win was to make Kerry even less palatable.

Obama is in a somewhat similar — albeit it slightly stronger — position that Bush found himself at this time in 2004. The struggling economy has dragged down the current incumbent’s numbers and two of his main legislative achievements — health care and the economic stimulus — are not popular with the American public. (They are popular with the Democratic base, however, which is why Obama is touting some of those accomplishments in web ads — a means of communication that helps gin up energy in the base.)

And, like Bush, Obama is a known commodity for voters while his opponents is not. And therein lies the opportunity for the incumbent. “Romney is vulnerable and now is the time to define the choice people have — between moving forward with Obama or back with Romney,” said Democratic media consultant Jason Ralston.

The best way to frame that devil you know/devil you don’t know line of attack is through a sustained campaign of negative ads in swing states.

Obama and his campaign team do take on some risk if they run a relentlessly negative (or close to it) ad campaign from here on out because he spent much of the 2008 election decrying those sorts of tactics — running on the twin messages of “hope” and “change”.

In a statement decrying the latest ad, Romney campaign spokeswoman Amanda Henneberg said President Obama is “trying to distract Americans from the real issues with a series of sideshows,” adding: “The American people have suffered enough over the last three years and deserve better.”

While the risk of being hoisted on his own petard is real for Obama, it’s clearly outweighed by the benefit of the damage these ads will do to Romney’s image in swing states.

Remember: Campaigns run negative ads because they work. The question is how long Romney’s conservative allies — Americans for Prosperity, American Crossroads — can carry the negative Obama message before Romney will have to start spending down his own campaign cash on pushback efforts.