“this delay of a state primary election, among others, understandably triggeredfears that other officials, potentially even Trump, might take advantage of the Ohio precedent to postpone or cancel November’s election if it appears that Trump is likely to be defeated.
The good news is that’s not allowed — or, at least, it’s not allowed unless Congress allows it to happen. A trio of federal laws set Election Day for presidential electors, senators, and US representatives as “the Tuesday next after the first Monday in November.” If Republicans want to change this law, they will need to go through the Democratic House.
The 20th Amendment, moreover, provides that “the terms of the President and the Vice President shall end at noon on the 20th day of January.” Thus, even if the election were somehow canceled, Trump and Vice President Mike Pence’s terms would still expire as scheduled — although, as explained below, the question of who would succeed them is devilishly complicated.
A more realistic threat, as the Nation’s Elie Mystal writes, is that state officials could use the extraordinary powers available to them during a major public health crisis to manipulate who is able to cast a ballot. It’s not hard to imagine a circumstance, for example, where the heavily Democratic counties of Miami-Dade and Broward, in Florida, are placed under a “shelter in place” order on Election Day, while residents of Republican counties in the panhandle are free to head to the polls.
But an outright cancellation of the election is unlikely in the extreme.”
…
“The picture for presidential elections is slightly more complicated. A federal statute does provide that “the electors of President and Vice President shall be appointed, in each State, on the Tuesday next after the first Monday in November,” so states must choose members of the Electoral College on the same day as a congressional election takes place.
That said, there is technically no constitutional requirement that a state must hold an election to choose members of the Electoral College. The Constitution provides that “each state shall appoint, in such manner as the Legislature thereof may direct, a number of electors, equal to the whole number of Senators and Representatives to which the State may be entitled in the Congress.” So a state legislature could theoretically decide to select presidential electors out of a hat. More worrisome, a legislature controlled by one party could potentially appoint loyal members of that party directly to the Electoral College.”
https://www.vox.com/2020/3/21/21188152/trump-cancel-november-election-constitution-coronavirus