Each of those has been justified at one time or another in our history (and some arguably worse). Except maybe the elections one. I'm not sure about that on any large scale. Well, we shifted our primary this year, but I don't know whether you would count that.
My point is that emergencies are what they are, and very difficult to define. That's why it is important to elect people who are - my words - of a responsible disposition to exercise that authority.
Which leads back to my point - vigilance. We need to be vigilant about making sure the "over-"reach doesn't extend beyond what is necessary. Fortunately, we do have the power of the ballot box (Trump's protestations notwithstanding) to un-elect leaders that abuse the power.
I'm trying to enumerate the nuance, but it seems that you're mostly taking the following, very absolute positions:
1. "Emergency" is a sufficient reason to infringe upon constitutionally protected rights and essential liberties, and "emergency" is a binary consideration
2. "Emergency" needs only a rational basis rationale for said infringement
3. If a constitutional right or essential liberty has been infringed/violated in the past due to any justification, it is fair game to be infringed/violated again
Since you seem to keep trying to paint me into the exact opposite corner, I think this is a fair/reasonable assessment of your positions. If these are your views, then I will indeed take the opposing, absolutist positions.
On the other hand, if we can agree that the two opposites represent two ends of a spectrum, perhaps we could instead have a discussion about where the appropriate middle ground is, and the basis for finding that middle ground.
(But if I'm forced to take one of the two, absolutist views, I'll gladly take the side that errs on the side of the philosophy articulated in the Declaration of Independence: "We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. — That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed...")