If Obama had moved early on Libya, it would be easy to condemn him for bogging us down in another armed conflict. There would be no counterfactual available to demonstrate hundreds would have been killed if the rebels weren’t protected via No-Fly Zone.
If Obama does nothing, Gaddafi eventually retakes all of Libya and those areas/peoples opposing him would be subject to massive reprisals. Obama is condemned for allowing a massacre to unfold.
Solution: Obama lets enough slaughter to go down that the media supports intervention. His opposition is split, now deriding the decision for a new entanglement after having first protested his lack of action in Libya. You think maybe they had one of those big thermometers stuck to the wall of the Oval Office like they have at fundraisers, waiting for the mercury to hit 2,000 before sending in the Air Force? 2,000 lives for about +/- 4 points in the polls is a pretty solid bargain. Well done, Mr. President, well done.