Three incumbents were defeated in the primary, two Democrats and one Republican.
Other than the Democratic trifecta that formed after the 2008 elections, Democrats had not had a trifecta since 1934.
Had the Republican Party maintained control of the chamber, it would have prevented a Democratic trifecta from forming in New York.
Democrats won nine of those elections, including seven in Republican-held seats, while Republicans won the remaining three.
Ballotpedia identified 12 of the races as battlegrounds, including 10 Republican-held districts and two Democratic-held districts.
All six lost their bids for re-election in the general election.
Five Republican incumbents were also defeated in the general election.
In the five presidential elections between 20, New York voted Democratic all five times.
The following table details results of the 20 presidential elections by state Senate districts in New York. The "Obama," "Romney," "Clinton," and "Trump" columns describe the percent of the vote each presidential candidate received in the district.
The New York State Senate was one of 87 state legislative chambers holding elections in 2018. The New York State Senate was one of 22 state legislative battleground chambers identified by Ballotpedia in the 2018 elections. New York state senators serve two-year terms, with all seats up for election every two years.