I believe the high mark was 34 GOP Governors after the 1920 elections (48 states). Plummeted to 22 with the disastrous 1922 midterms. 24 in 1924. 26 in 1926 (I’m not making this up, 3 elections in a row with the GOP winning the same number as the year !). 29 were in office in 1929.
1930 dropped to 20. 1932 dropped to 8(!). 1934, 9. 1936, the nadir of the 20th century: 7 out of 48. Regained 10 in 1938 to 17 out of 48.
“I’m not making this up, 3 elections in a row with the GOP winning the same number as the year “
Tee hee, too bad it keep up.