Abraham Lincoln once explained his behavior as president-elect during his transition period, and the reasons for it.
During his pre-inauguration trip to Washington, D.C. in 1861, Lincoln talked to a gathering of Republican Clubs at the Astor House in New York City.
After he opened with remarks about being unprepared to speak, and about some of the great speakers who had used that same room in the past, Lincoln explained his general absence from the public eye since November. [All bolding is mine for your attention.]
I have been occupying a position, since the Presidential election, of silence, of avoiding public speaking, of avoiding public writing. I have been doing so because I thought, upon full consideration, that was the proper course for me to take.
At the crowd reaction, Lincoln added some of his wry humor here in the next line. [Please note: Except for this following section and the last one, I removed the applause brackets from all the other parts of this speech for the sake of clarity and reading.]
(Great applause.) I am brought before you now and required to make a speech, when you all approve, more than anything else, of the fact that I have been silent–(loud laughter, cries of ‘Good–good,’ and applause)–and now it seems to me from the response you give to that remark it ought to justify me in closing just here. (Great laughter.) 
Lincoln, during the months after his election in November, 1860, remained out of the public eye, even as the South escalated its threat to the Union with the secession of seven states and the election of its own president.
Despite the uproar, Lincoln said a president-elect’s silence didn’t mean the events or the people’s anxieties about those events were unimportant. His train trip to Washington, D.C. was filled with stops and “unplanned” speeches of just this nature – to explain his silence as he did in the Astor House.
I have not kept silent since the Presidential election from any party wantonness, or from any indifference to the anxiety that pervades the minds of men about the aspect of the political affairs of this country.
Unlike his modern counter-parts, Lincoln felt that silence was the proper behavior of a president-elect until he formally assumed the office as president.
I have kept silent for the reason that I supposed it was peculiarly proper that I should do so until the time came when, according to the customs of the country, I should speak officially.
Lincoln even further clarified that, as he understood ‘the custom of the country,’ he should not officially speak until the inauguration ceremony.
I heard some gentleman say, ‘According to the custom of the country;’ I alluded to the custom of the President elect at the time of taking his oath of office. That is what I meant by the custom of the country.
Another savvy political reason that Lincoln used silence was to avoid premature positions that circumstances might change by the time the president-elect assumed office.
I do suppose that while the political drama being enacted in this country at this time is rapidly shifting in its scenes, forbidding an anticipation with any degree of certainty to-day what we shall see to-morrow, that it was peculiarly fitting that I should see it all up to the last minute before I should take ground, that I might be disposed by the shifting of the scenes afterwards again to shift.
President-elect Lincoln saw the political wisdom in using the trip to Washington as an opportunity to reassure everyone (the South in particular) that he viewed the president’s job as a non-partisan one with regards to decision-making.
I said several times upon this journey, and I shall now repeat it to you, that when the time does come I shall then take the ground that I think is right — the ground I think is right for the North, for the South, for the East, for the West, for the whole country.
Lincoln offered another argument that waiting to take a stand also would keep him from inadvertantly saying something that might cause more problems during such a turbulent time or that might be inconsistent with any of the positions for which he stood during the election campaign.
And in doing so I hope to feel no necessity pressing upon me to say anything in conflict with the constitution, in conflict with the continued union of these States, in conflict with the perpetuation of the liberties of these people — or anything in conflict with anything whatever that I have ever given you reason to expect from me.
So, in Abraham Lincoln’s viewpoint, a president-elect, during the transition period, should act accordingly for customary and political reasons:
- Maintain public silence – both speaking and writing – until officially inaugurated;
- Avoid taking any unofficial public stands on issues that unfold after the election to prevent the possibility of having to change that position after the inauguration;
- Act in a manner consistent with the candidate’s campaign positions;
- Reassure the country that he/she will be a bi-partisan leader.
These behaviors – being low-key and avoiding distracting publicity until after the inauguration – also show respect for the outgoing administration and for all the citizens of the country, regardless of party.
And now, my friends, have I said enough (Cries of ‘No, no,’ ‘Go on,’ &c.) Now, my friends, there appears to be a difference of opinion between you and me, and I feel called upon to insist upon deciding the question myself.
That last remark was Lincoln’s only real forcast of his coming presidency – a buried double entendre in his closing statement that he alone would make the final decisions and own the responsibilty for them. He followed through with that promise for four years.
After all, a president-elect’s behavior demonstrates his/her respect for all – wasn’t that ultimately Lincoln’s point?
Food for thought.
 “Speech at the Astor House – February 19, 1861.” The Collected Works of Abraham Lincoln, Volume IV, p. 230-231.