“I think it’s a fair point to raise as to whether or not if he loses he’s going to go quietly or not, and we have to be ready for that,” Mr Trump’s defeated 2016 opponent said in a television interview on Monday night.
Speaking to The Daily Show’s Trevor Noah from her home in Chappaqua, New York, Ms Clinton said she believed the president and other Republicans were scaremongering about voter fraud to try to undermine the presidential election before it took place.
On the issue of fraudulent mail-in ballots, which Mr Trump has loudly talked up in recent weeks, Ms Clinton said: “There have been so many academic studies and other analyses which point out that it’s just an inaccurate fraudulent claim. There isn’t that problem.”
Some have speculated that Mr Trump may use his professed mistrust of mail-in ballots as a basis for post-election claims that November’s eventual vote – if he loses it – was rigged or stolen and therefore not to be trusted.
For his part, Joe Biden has said he is confident the US Army can be trusted to peacefully escort Mr Trump from the White House should he refuse to give up power.
The orderly transfer of the presidential office was also a worry in 2016, when the depth and intensity of political division raised concern that violent protests might break out whichever candidate won.
Ms Clinton acknowledged those concerns in her concession speech in New York, when she called on her side to accept the result and move on.
“Our constitutional democracy enshrines the peaceful transfer of power,” she said then. “We don’t just respect that. We cherish it. It also enshrines the rule of law; the principle we are all equal in rights and dignity; freedom of worship and expression.”
During her Daily Show interview, Ms Clinton also claimed that Republican governors and state legislatures were making it harder for people to vote by cutting the number of polling stations, purging voter rolls and making it harder to register.