Two governorships which have been under single-party control for 40 years are on the ballot in 2020

Four of the twelve states holding gubernatorial elections in 2020 have not seen the office change hands since the 20th century.
The longest winning streak on the 2020 ballot is in Utah, where Republicans have won the past 10 gubernatorial elections. Should Republicans win their 11th consecutive gubernatorial election in the state, they would surpass the 10-election winning streak Oregon Democrats secured in the 2018 elections, which currently ties Utah for the longest streak. A win for Democrats would be their first in 40 years.
In Washington, the opposite is true—no Republican has won election to the state’s highest office since 1980. Republicans are seeking their first win in 40 years while Democrats are looking to extend their nine-election winning streak. Both Utah and Washington have gubernatorial winning streaks that started in 1984, but Utah held a special election in 2010, giving Republicans one win more.
Delaware and North Dakota have had the same party in the governorship since 1992. Delaware Republicans and North Dakota Democrats are seeking their first electoral victories in nearly 30 years as first-term governors John Carney (D-Del.) and Doug Burgum (R-N.D.) aim to win their party’s eighth consecutive elections.
Meanwhile, two states holding gubernatorial elections in 2020 saw control of the office change hands in the previous election. Republicans won Missouri in 2016 after two cycles under Democratic control. Democrats won North Carolina in 2016 after one term of Republican control.