First of all she is beating him by large margins and even in some red states. Second, the reason your theory is flawed is because everytime she isn’t running for something she is voted the ‘most admired woman in the world’. What you don’t take into account is all the sexism which is part of the Clinton-hate. If Dems put up Nancy Pelosi or even Elizabeth Warren, the other side would be going after them, their past, their husbands, all their connections to anything just as viciously as they attack Hillary. Beside a “should of” is not really a strategy.