As Democrats meet to 'line up candidates amid health scare.....What happens if Hillary Clinton drops out?

Mrs Clinton was caught on camera being helped into a van after she appeared to faint at a 9/11 memorial.

Her doctor later confirmed she had been suffering from pneumonia. Dr Lisa Bardack said Mrs Clinton was “recovering nicely” following the incident, which follows months of speculation around the 68-year-old’s health.....

David Shuster, a top US journalist, says that the election has entered “unchartered political territory” after Mrs Clinton’s diagnosis.

He quoted a Democratic party operative as saying: “Expect an emergency Democratic National Convention (DNC) meeting to consider a replacement.”

The source confirmed to Mr Shuster that Mrs Clinton would have to voluntarily give up the party nomination, saying: “We can make contingencies, argue, plead with her, but DNC bylaws are clear her nominee status is now totally up to her.”.....  Should Mrs Clinton drop out of the race, the DNC would hold a special meeting to vote for a successor. Party rules indicate that a new nominee would be elected by a simple majority vote?

Many states offer early voting, with residents of Minnesota and South Dakota able to hand in their ballots as early as September 23. 

A replacement would need to be added to the ticket before ballots are sent out, as in some states only votes for candidates printed on the slip can be counted.