The Democratic Party performed strongly in federal elections with incumbent Democrats winning re-election to all five Connecticut seats in the U.S. House of Representatives by more than 10 points, and incumbent U.S. Senator Chris Murphy winning re-election by 20 points. Democrats also performed strongly in the Connecticut General Assembly, gaining 12 seats in the State House of Representatives and 5 seats in the State Senate. However, this "blue wave" did not transfer to all state elections.[2] Although typically considered a "blue state", no Democrat had won a gubernatorial election in the state by more than 5 points since 1986. This continued in 2018, with Democratic nominee Ned Lamont only winning the governorship by 3 points.
Two-term incumbent Democratic Governor Dannel Malloy and Lieutenant Governor Nancy Wyman were eligible for a third term but declined to run for re-election. Democratic nominees Ned Lamont and his running mate Susan Bysiewicz won the election against Republican nominees Bob Stefanowski and Joe Markley.
Two-term incumbent Democratic State Attorney General George Jepsen did not seek re-election. Democratic nominee and state representative William Tong defeated Republican nominee Susan Hatfield.