2018 United States Senate elections in the context of Jeff Sessions

The 116th United States Congress was a meeting of the legislative branch of the United States federal government, composed of the Senate and the House of Representatives. It convened in Washington, D.C., on January 3, 2019, and ended on January 3, 2021, during the final two years of Donald Trump's first presidency. Senators elected to regular terms in 2014 finished their terms in this Congress, and House seats were apportioned based on the 2010 census.

In the November 2018 midterm elections, the Democratic Party won a new majority in the House, while the Republican Party increased its majority in the Senate. Consequently, this was the first split Congress since the 113th Congress of 2013–2015, and the first Republican Senate–Democratic House split since the 99th Congress of 1985–1987. This Congress was the youngest incoming class by mean age, compared to the previous three the incoming class of freshman representatives, and the most demographically diverse in history.

The 2018 Ohio gubernatorial election took place on November 6, 2018, to elect the next governor of Ohio, concurrently with the election of Ohio's Class I U.S. Senate seat, as well as other elections to the United States Senate in other states, elections to the United States House of Representatives, and various Ohio and local elections. Incumbent Republican Governor John Kasich was term-limited and could not seek a third consecutive term.

Republicans nominated Ohio Attorney General and former U.S. senator Mike DeWine, while Democrats nominated former Consumer Financial Protection Bureau Director and former Ohio attorney general Richard Cordray. This was the second contest between DeWine and Cordray, following the 2010 attorney general election, which DeWine won, 47.5% to 46.3%.

Elections were held in the United States on November 6, 2018. These midterm elections occurred during incumbent Republican president Donald Trump's first term. Although the Republican Party increased its majority in the Senate, Democratic incumbents and challengers vastly outperformed Trump's margin in Republican-leaning states, and unified Republican control of Congress and the White House was brought to an end when the Democratic Party won control of the House of Representatives. In what was widely characterized as a "blue wave" election, Democrats also gained governorships, other statewide offices, and state legislative chambers.

Democrats made a net gain of 40 seats in the United States House of Representatives, gaining a majority in the chamber and thereby ending the federal trifecta that the Republican Party had established in the 2016 elections. The Republican Party retained control of the United States Senate, making a net gain of two seats and defeating four Democratic incumbents in states that had voted for Trump in 2016. As a result of the 2018 elections, the 116th United States Congress became the first Congress since the 99th United States Congress (elected in 1984) in which the Democrats controlled the U.S. House of Representatives and the Republicans controlled the U.S. Senate. In state-level elections, Democrats picked up a net of seven governorships and several state legislative seats.