Many presidential candidates change their position and view on issues. Their core supporters always stand by them, and the change in stance will often help them expand their appeal. Donald Trump has been increasing in popularity recently as he softens some of his rhetoric and alters his position on some issues.
Many of Trump's supporters will forget about his previous controversial statements. Some Independents and Democrats will also overlook these bombastic statements because of their dislike for Hillary Clinton. Therefore, Trump's previous statements may not hurt his candidacy that much. Much of the electorate is turned off by Clinton, so a lot of voters will be voting against her.
Unfortunately in the fast world of media people do seem to forget very easy. This is probably caused by a mix of social media and the relentlessness of the main stream media. Due to the nature of modern media I think people do forget political statements very easily, because of this I think lots of voters will forget about Trump's statements, which is a big shame because they would do well to remember what he said.
Yes, I believe that voters will forgive and forget any inflammatory statements made by Donald Trump's campaign manager. I believe this is true because voters want to believe that Trump is a source of change and don't want to view him negatively. Also, I believe that the beliefs of the campaign manager don't necessarily represent Trump's views, so voters should not hold his remarks against Trump.