Political speech. There is no absolute protection for speech based on politics as subject matter alone.
Immediate issue: Candy Crowley as moderator of a presidential/candidate debate, and any other present and functioning entity where the discussion arises, must call the foul shot before the damage of instant communication and instant persuasion as to that essential fact, the conduct of the official, is accomplished. The public interest requires it.
The allegation: The President engaged in certain moves.
But did he? Or was that some imagined Elvis? The stakes are high. Catch the voter unawares, and perhaps an unwary voter will believe what comes over the airwaves, irrevocably.
Look at political lies. No absolute protection. Lies about what an elected official did, the formal conduct itself, is a matter of record, not argument. For example, did a President gut any requirement in effect as to work and welfare. Unfounded claims of official action cannot serve as the basis for derivative argument: that this President gutted a work requirement. What exactly did he do to change the playing field from before?
Political argument arises as to effect of official actions. There are limits on lying. Electioneering and puffing is fine to rouse a base; but only acceptable up to and not including material misrepresentation of the actual act of the official. See No Protection for Misstatement of Official Conduct. Argument as to the effect and desirability are fine; not lying about what the official actually did. Crowley was right. Whoever is there at the time and with the capacity to intervene to prevent blatant voter exploitation by lies about official conduct, shall, shall, shall do so.
Test that against allegations that an official (here, President Obama) has gutted welfare's requirement for work. See http://www.heritage.org/issues/welfare/work-and-welfare
What exactly did the President do as President to dismantle workfare? What did he sign? What rules did he change? If more people were eligible because of an economic disaster, and learned of the statutory benefit that could be available, what is the official act cutting out a work requirement?
Candy Crowley. Step up as a journalist and ask.