You might hear pundits say mid-term reversals are common. Not so much.
It did happen in 2006 (Bush) and 1994 (Clinton) and 1986 (Reagan). We’re talking once per decade.
But in 2002 (Reagan), the White House picked up the Senate; it flipped the other way.
From 1955 – 1981, the Senate was solid D, regardless of the White House incumbent. [icopyright one button toolbar]
Contrary to popular belief, most of the time (in modern political history) Congress and the President are at odds; that is, most of the time the same political party does not control the White House, the Senate, and the House of Representatives. Only 13 times (26 years) since 1945 have both branches of Congress and the Presidency been controlled by the same party; the Democrats have held this advantage more often than Republicans (11 to 2).
See the chart (below) as a web page.

Known for gnawing at complex questions like a terrier with a bone. Digital evangelist, writer, teacher. Transplanted Southerner; teach newbies to ride motorcycles. @kegill (Twitter and Mastodon.social); wiredpen.com