He'll say whatever it takes to get elected. His core voters know he's lying and so will vote for him anyway. The soft, squishy middle will use this as an excuse to vote for him. Very smart. And very cynical.
Of course he does. My take's different. It shows him as stupid and unprincipled. This is not a man who can be trusted to be loyal to your cause. The Democrats in nominating a stealth candidate, may well find they picked someone they can't trust. It goes both ways.