I've seen this tactic in every major election. It's the "both sides do it" gambit, an attempt to lessen the impact of negative disclosures about their candidate's latest shenanigans. The message: One guy is no better (or worse) than the other. You can't get mad at our guy when their guy is just as guilty of these improprieties.
Of course, Romney told no lies. He stated, correctly, that Obama had gutted the welfare reform that President Clinton and a Republican Congress created some years back. Obama removed the work requirement in order to receive welfare. When Romney complained about it, the Obama camp exploded in paroxysms of outrage, saying it was all a lie, a gross misrepresentation, etc. However, no Democrat has yet pointed to the alleged falsehoods,errors or misrepresentation, let alone refute them. Obama claimed that some Republican governors had asked for waivers, allowing them to give out welfare without a work requirement. However, no such governors exist.
Obama had simply lied again. If caught, expect the Democrat media to start another round of "both sides do it." Be not fooled by this well-worn gambit. Without the lies, the Democrats would have no arguments at all.