Is 2016-2020 the least electoral shift between any two consecutive elections?

[David Hume]

I define relative electoral shift as follow

Difference of sum of the two party percentage margin times electoral vote of each state, divided by total electoral votes.

I don't have time to code, but a quick glance of data seems to support this.

[pbrower2a]

If you are counting states or electoral votes shifting, 2000 to 2004 is but three, and 2008 to 2012 is but two states and one district, but with more electoral votes.

[Orser67]

In addition to what PBrower pointed out, some other examples of low-shift consecutive elections are 1796/1800, 1920/1924, 1940/1944, and 1952/1956. The whole period from 1880-1908 also didn't see many shifts.

2000-2004 saw a shift of just 16 electoral votes, a 2.97% share of the electoral vote, and a net shift of 11 electoral votes (since NH and NM mostly cancel each other out), which represents 2.04% of the electoral vote. 1904-1908 also saw a shift of 16 electoral votes, with a net shift of 15, but there were 476 EVs so the percentages are a little higher compared to 2004. 1796-1800 saw a shift of 21 electoral votes, but the shifts largely canceled out for a net gain of 5 for Jefferson; those 5 votes represented 3.62% of the electoral vote (without getting into the details of pre-12th Amendment elections). Purely in terms of the number of states flipped, I think the record is 1884/1888, when just IN and NY flipped (technically it ties 2008-2012, but I think the lack of a flipped district in another state gives it the tiebreaker).

If we focus less on just the number of electoral votes, it's striking how much consistency there was between 1880-1888. Just five states voted for both parties during this period (CT, NY, IN, CA, and NV), and each candidate received between 47.8% and 48.9% of the national popular vote. Each election essentially came down to New York, which was won by a percentage margin of R+1.9%, D+0.1%, and R+1.1%.