The 1984 United States Senate elections were held on November 6, with the 33 seats of Class 2 contested in regular elections. They coincided with the landslide re-election of President Ronald Reagan in the presidential election. In spite of the lopsided presidential race, Reagan's Republican Party suffered a net loss of two Senate seats to the Democrats, although it retained control of the Senate with a reduced 53–47 majority. Democrats defeated incumbents in Illinois and Iowa, and won an open seat in Tennessee, while Republicans defeated an incumbent in Kentucky.
The 1978 United States Senate elections were held on November 7, in the middle of Democratic President Jimmy Carter's term. The 33 seats of Class 2 were contested in regular elections. Special elections were also held to fill vacancies.
The 1966 United States Senate elections were elections on November 8, 1966, for the United States Senate which occurred midway through the second term of President Lyndon B. Johnson. The 33 seats of Class 2 were contested in regular elections. Special elections were also held to fill vacancies. With divisions in the Democratic base over the Vietnam War, and with the traditional mid-term advantage of the party not holding the presidency, the Republicans took three Democratic seats, thereby breaking Democrats' 2/3rds supermajority. Despite Republican gains, the balance remained overwhelmingly in favor of the Democrats, who retained a 64–36 majority. Democrats were further reduced to 63–37, following the death of Robert F. Kennedy in June 1968.
The 2008 United States Senate election in Illinois was held on November 4, 2008. Incumbent Democratic U.S. Senator Dick Durbin sought a third term in office and faced minimal opposition from Republican Steve Sauerberg. As expected, Durbin overwhelmingly won re-election. On the same night, fellow Democratic Senator Barack Obama was elected President of the United States, defeating Republican Senator John McCain of Arizona.
The 1996 United States Senate election in Illinois took place on November 5, 1996. Incumbent Democratic U.S. Senator Paul Simon chose to retire rather than seek a third term in office. In the Democratic primary, U.S. Representative Dick Durbin emerged victorious, while state representative Al Salvi won the Republican primary. Though the election was initially anticipated to be close, Durbin ended up defeating Salvi by a comfortable double-digit margin of victory, allowing him to win what would be the first of several terms in the Senate.
The 1990 United States Senate election in Illinois was held on November 6, 1990. Incumbent Democratic U.S. Senator Paul Simon sought re-election to a second term in office. Simon was opposed by Republican nominee Lynn Morley Martin, a U.S. Congresswoman from Illinois's 16th congressional district, whom he easily defeated to win a second and final term in the Senate.
The 1984 United States Senate election in Illinois took place on November 6, 1984. Incumbent Republican Senator Charles H. Percy ran for re-election to a fourth term in the United States Senate. Senator Percy was opposed by Democratic nominee Paul Simon, who was a United States Congressman from Illinois's 22nd congressional district. The campaign between Percy and Simon was contentious and brutally fought, and ended up with Simon ousting Percy by fewer than 90,000 votes, which was, at the time, considered an upset. Incidentally, Percy's son-in-law Jay Rockefeller was elected Senator from West Virginia in the same election cycle.
The 1978 United States Senate election in Illinois took place on November 7, 1978. Incumbent Republican United States Senator Charles H. Percy ran for re-election to a third term in the United States Senate. Percy was opposed by Democratic nominee Alex Seith, an attorney who had been appointed to several local government positions.
The 1972 United States Senate election in Illinois took place on November 7, 1972. Incumbent Republican United States Senator Charles H. Percy sought re-election to the United States Senate. Percy was opposed by Democratic nominee Roman Pucinski, a United States Congressman from Illinois's 11th congressional district, whom he was able to defeat handily to win a second term. As of 2022, this was the last time a Republican was elected to the U.S. Senate from Illinois during a presidential election year, the last time an Illinois Republican won a Senate election by double digits, and the last time any candidate has swept every county in the state. This election was the fourth consecutive time in which a United States Senate election in Illinois took place two years after a previous United States Senate election in Illinois after 1966, 1968 and 1970.
The 1992 United States presidential election in Illinois took place on November 3, 1992, as part of the 1992 United States presidential election. Voters chose 22 representatives, or electors to the Electoral College, who voted for president and vice president.
The United States Senate election in Illinois of 1954 took place on November 2, 1954. Incumbent Democratic United States Senator Paul Douglas was reelected to a second term.
The 1960 United States Senate election in Illinois took place on November 8, 1960. Incumbent Democratic United States Senator Paul Douglas was reelected to a third term.
The 1970 United States Senate special election in Illinois was held on November 3, 1970, to fill the remainder of the term of Republican Everett Dirksen, who had died in office. Republican Ralph Tyler Smith had been appointed to fill the seat after Dirksen's death, and he lost the special election to Democrat Adlai Stevenson III. This election was the third consecutive time in which a United States Senate election in Illinois took place two years after a previous United States Senate election in Illinois after 1966 and 1968.
The 1974 United States Senate election in Illinois took place on November 5, 1974. Incumbent Democratic U.S. Senator Adlai Stevenson III, who was first elected in a special election in 1970, was re-elected to a full term in office, defeating Republican George Burditt by a large margin of nearly 800,000 votes. This election was the fifth consecutive time in which a United States Senate election in Illinois took place two years after a previous United States Senate election in Illinois after 1966, 1968, 1970 and 1972.
The 1964 Illinois gubernatorial election was held in Illinois on November 3, 1964. The Democratic nominee, incumbent Governor Otto Kerner, Jr., won reelection against the Republican nominee, Charles H. Percy.
Elections were held in Illinois on Tuesday, November 6, 1984.
Elections were held in Illinois on Tuesday, November 8, 1966.
Elections were held in Illinois on Tuesday, November 3, 1964.
Elections were held in Illinois on Tuesday, November 8, 1960.
Elections were held in Illinois on Tuesday, November 3, 1936.
