Umm....Hillary is an incredibly weak candidate. Any competent Democrat would be killing it against Trump and she might actually lose.
No. Democrats could nominate Mother Theresa and Republicans would still coalesce around Trump and tear her down as unacceptable.
They have been brainwashed all these years by the right wing media that any Democratic president is an illegal usurper, hellbent on destroying America, and he/she should be treated accordingly.
So in the hypothetical world where the 22nd amendment didn't exist and Obama was running for his 3rd term, he wouldn't be doing better than Clinton? Clinton is not a very good politician. We don't know why the hell she is running.