Nah, this has nothing to do with Obama’s 2012 reelection efforts.

(Politico) — President Barack Obama took on the entire GOP presidential field Monday — mocking their collective pledge to block even the slightest attempt to raise taxes on the rich — while singling out Mitt Romney for particularly scathing ridicule over his health reform stance.

Obama seemed happy to go on the attack after absorbing a week of withering criticism from Republican presidential hopefuls campaigning in nearby Iowa. He joked that he would own “Obamacare,” the GOP’s derisive description of his massive health care reform effort.

Emerging from the bus, Obama lit into Romney, accusing the former Massachusetts governor of ditching his commitment to health care reform to run in the conservative GOP primary: “You got a governor who is running for president. . . . It’s like [he’s] got amnesia.”

He even mimicked Romney: “Oh, this is terrible! This is going to take away freedoms!”

The audience was largely supportive, but there were murmurs of concern about the jobs crisis and the president’s willingness to accept some changes to entitlements such as Medicare and Medicaid.