Mitt Romney, asked if there were any lessons learned in the wake of losing all three Republican voting contests Tuesday night, said that he simply “wasn’t there to respond” to former Sen. Rick Santorum’s attacks in the days leading up to voting. But today, speaking to reporters on a tarmac in Atlanta, where he flew from Colorado after losses in Minnesota, Missouri and Colorado Tuesday night, he did not hesitate to go on offense, accusing two chief GOP rivals of behaving “like Democrats.”