I searched here and on Google, came up with nothing definitive but then I’m not a Google expert by any means.
All I found was an article that said Richard Nixon wanted a constitutional amendment to allow this, but I didn’t find anything to indicate that it was ever seriously considered.
So can the President (or anyone) declare a national emergency and suspend elections?
Is this one of those things that we won’t know can happen until it does?
Do you mean postponed until next week or postponed until the President feels like it?
They had a presidential election during the Civil War, so I’m wondering just what bigger problem we’d be looking at.
Elections are a combination of state and Federal laws, so the answer would be “it depends”.
Primary elections in NYC were delayed in 2001 as they were originally scheduled for 9/11.
Natural disasters would be a more likely reason for a delayed election than any other “emergency” I would think.
Earl, I guess postponed “until he feels like it.”
In the event we had a president who felt like he was the only one who could manage a crisis.
I’d like to think it couldn’t happen, that the election process is so embedded in our democratic psyche that we just wouldn’t allow it.
But whenever I say “it’ll never happen”, it does. But usually it’s about little things, like the pipes won’t freeze or the dog won’t get loose. 
Thanks Earl and Bob. I’m a bit reassured.
Well, remember, the President’s term doesn’t end on Election Day. He’d have until January 20th to finish the job if he’s not re-elected.
I’d consider the President postponing elections to be a grand breach of power in most cases.
Well, even if President lost an election in November, his successor won’t be sworn in until late January, giving the current Prez more than two months to deal with a particular crisis.
If he went visibly nuts, declaring long and loud that only HE could manage the current crisis, the cabinet would (I hope) smile and nod, smile and nod, and quietly put the Vice-President in charge (25th Amendment, paragraph 4) and let the election proceed normally. Of course, under such conditions, the incumbent would almost certainly be voted out.
Not on a national level, but the New York mayoral and city council primaries were delayed following 9-11 (in fact, they were originally on 9-11. No New York constitutional crisis ensued, and despite some maneuvering a new mayor was duly installed on schedule.
Part of the reason why elections are held many weeks or months before the term of office begins is precisely so they can be moved is emergency situations demand it. Each state maintains its own election laws and has their own procedures for cancelling elections and stuff. The President could not legally hold office after Jan 20th if he was not re-elected by the electoral college, but there’s plenty of time between election day and then to reschedule elections if there is some emergency that would prevent them.
In fact, I don’t think there’s any particular requirement that mandates all states hold Presidential elections on the same day, since each state is permitted to appoint its electors in pretty much any way it chooses.
Actually, there is such a requirement:
Const., art. II, sec. 1. Pursuant to the constitutional provision, the law provides that
Any chance we could get them to do that to Bush? 
[ducking & running]
Seriously, President Lincoln had to run for re-election while half the nation was in a state of armed rebellion, so the historical precedent is a rather definite “No!”
The 25th amendment is one route to rescuing an election from a megalomaniac president. But a president who ordered an election postponed or canceled probably couldn’t make it stick in any case. Not only is there no constitutional or statutory authority for such a presidential action, no part of the electoral machinery is in the hands of the president or his or her subordinates. The states appoint the electors, who vote in their states, and the certificates evidencing their votes are widely disseminated in case anything “accidentally” happens to the original certificate that they “transmit sealed to the seat of the government of the United States”:
3 U.S.C. § 11. Even if the vice president, in his or her capacity as president of the Senate, is in on the deal with the president, at least one copy is still in the state’s hands:
3 U.S.C. § 12.And a copy is in a court’s hands:
Thus, a president can declare whatever he or she likes, but the states and Congress can go ahead with the election anyway. An election could not be postponed or canceled just on the president’s say-so unless there was either a very broad consensus or a very broad conspiracy in favor of such an action.
The USA also has enormous precedent against postponing national elections during crisis. Elections were held during the Civil War and World War II. And during the Civil War, McClellan campaigned vigorously against Lincoln and in favor of a negotiated settlement of the war.
It’s true that a President saying “the election is cancelled” has no weight of law, but we can postulate a worst-case scenario where a bonkers President starts dispatching federal troops to bust up polling stations and whatnot. Those sorts of shenangians have happened in plenty of places, though I personally doubt the U.S. could ever get that far.
Reading some of the Pit threads about Bush and Rumsfeld suggests quite a few SDMB members feel otherwise.