Q Is it too late for Republicans to replace Mr Donald Trump?
A The Republican Party does not have a mechanism to replace a nominee just because it wants to.
The party's rules state that "the Republican National Committee (RNC) is hereby authorised and empowered to fill any and all vacancies which may occur by reason of death, declination, or otherwise of the Republican candidate for president of the United States".
That essentially means that Mr Trump would have to die, become incapacitated or voluntarily step down for the party to replace him. But he has said he would not quit the race.
Q What if the Republicans really want to dump Mr Trump?
A The RNC could try to change its rules (or its rules about changing rules) and come up with a new way to find a different nominee. This would probably trigger chaos in the party and cause Mr Trump and his supporters to declare the process "rigged".
Q What if Mr Trump does decide to quit the race?
A The RNC would have to rush to find a replacement that members could agree on. The rules committee would scramble to determine who would be eligible to be nominated and how such a nomination would proceed.
The 168 RNC members representing state delegations would have to hold a vote and, as Mr Trump did at the convention in Cleveland, the new nominee would need to win at least 1,237 delegates to become the party's standard-bearer.