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. This was the first time since 1972 that Democrats gained Class 2 Senate seats.

Results summary

+ ↓ 47 53 Democratic Republican

Parties Total Democratic Republican Libertarian Other Last elections (1982) 46 54 0 0 100 Before these elections 45 55 0 0 100 Not up 31 36 — — 67 Up 14 19 — — 33 Incumbent retired 2 2 — — 4 2 1 — — 3 1 Republican replaced by 1 Democrat — — 1 Result 3 1 — — 4 Incumbent ran 12 17 — — 29 11 15 — — 26 2 Republicans replaced by 2 Democrats 1 Democrat replaced by 1 Republican — — 3 0 0 — — 0 Result 13 16 — — 29 Total elected 16 17 0 0 33 Net gain/loss 2 2 2 Nationwide vote 23,079,278 22,850,493 160,798 232,231 46,322,800 Share 49.82% 49.33% 0.35% 0.50% 100% Result 47 53 0 0 100

Source: Office of the Clerk

Gains, losses, and holds Retirements Two Republicans and two Democrats retired instead of seeking re-election.

StateSenator Age at end of term AssumedofficeReplaced by Massachusetts 43 1979 Tennessee 59 1967 Texas 1961 West Virginia 82 1958

Defeats Two Republicans and one Democrat sought re-election but lost in the general election.

StateSenator AssumedofficeReplaced by Illinois 1967 Paul Simon Iowa 1979 Kentucky 1973

Post-election changes

StateSenatorReplaced by North Carolina

Change in composition Before the elections D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D R R R R R Majority → R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R

After the elections D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D R R R Majority → R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R Key D Democratic R Republican

Race summary

Special elections There were no special elections to the U.S. Senate in 1984.

Elections leading to the next Congress In these general elections, the winners were elected for the term beginning January 3, 1985; ordered by state.

All of the elections involved the Class 2 seats.

State Incumbent Result Candidates Senator Party Electoral history Alabama Democratic 1978 Incumbent re-elected. Alaska Republican 1968 197019721978 Incumbent re-elected. Arkansas Democratic 1978 Incumbent re-elected. Colorado Republican 1978 Incumbent re-elected. Delaware Democratic 19721978 Incumbent re-elected. Georgia Democratic 1972 19721978 Incumbent re-elected. Idaho Republican 19721978 Incumbent re-elected. Illinois Republican 196619721978 Incumbent lost re-election.Democratic gain. Iowa Republican 1978 Incumbent lost re-election.Democratic gain. Kansas Republican 19781978 Incumbent re-elected. Kentucky Democratic 19721978 Incumbent lost re-election.Republican gain. Louisiana Democratic 1972 19721978 Incumbent re-elected. Maine Republican 1978 Incumbent re-elected. Massachusetts Democratic 1978 Incumbent retired for health reasons.Democratic hold.Incumbent resigned January 2, 1985 to give successor preferential seniority.Winner appointed the same day. Michigan Democratic 1978 Incumbent re-elected. Minnesota Republican 19781978 Incumbent re-elected. Mississippi Republican 19781978 Incumbent re-elected. Montana Democratic 19781978 Incumbent re-elected. Nebraska Democratic 1978 Incumbent re-elected. New Hampshire Republican 1978 Incumbent re-elected. New Jersey Democratic 1978 Incumbent re-elected. New Mexico Republican 19721978 Incumbent re-elected. North Carolina Republican 19721978 Incumbent re-elected. Oklahoma Democratic 1978 Incumbent re-elected. Oregon Republican 196619721978 Incumbent re-elected. Rhode Island Democratic 1960196619721978 Incumbent re-elected. South Carolina Republican 1954 (write-in)1954 1956 1956 1960196619721978 Incumbent re-elected. South Dakota Republican 1978 Incumbent re-elected. Tennessee Republican 196619721978 Incumbent retired.Democratic gain. Texas Republican 1961 196619721978 Incumbent retired.Republican hold. Virginia Republican 19781979 Incumbent re-elected. West Virginia Democratic 1958 1960196619721978 Incumbent retired.Democratic hold.Winner seated January 15, 1985 to finish term as Governor of West Virginia. Wyoming Republican 19781979 Incumbent re-elected.

Closest races

In six races the margin of victory was under 10%.

State Party of winner Margin Kentucky Republican (flip) 0.41% Illinois Democratic (flip) 1.86% West Virginia Democratic 3.09% North Carolina Republican 3.85% Nebraska Democratic 3.92% Michigan Democratic 4.61%

Minnesota was the tipping point state with a margin of victory of 16.8%.

Alabama

The 1984 United States Senate election in Alabama was held on November 6, 1984. Incumbent Democratic Senator Howell Heflin was easily re-elected to a second term. Heflin received 94% of the black vote.

Alaska

Incumbent Republican Ted Stevens sought re-election to a fourth term. Owing to his popularity and the conservative bent of Alaska, Stevens did not face major opposition, and easily defeated former Alaska Attorney General John Havelock in the general election.

Arkansas

Incumbent Democrat David Pryor won re-election to a second term over Republican U.S. Representative Ed Bethune.

Colorado

Incumbent Republican William L. Armstrong won re-election to a second term over Democratic Lieutenant Governor of Colorado Nancy Dick.

Delaware

Incumbent Democrat and future President of the United States Joe Biden won re-election to a third term, defeating Republican challenger John M. Burris, former Majority Leader of the Delaware House of Representatives.

Georgia

Incumbent Democrat Sam Nunn won re-election to a third term over Republican educator, Mike Hicks

Idaho

Incumbent Republican James A. McClure won re-election to a third term over Democratic Vietnam War veteran, Peter M. Busch.

Illinois

Incumbent Republican 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 brutal and toughly-fought, and ended up with Simon ousting Percy by fewer than 90,000 votes, which was, at the time, considered an upset.

The election was very close. Simon prevailed by only 89,126 votes, or 1.86%. Incumbent Percy did well all throughout the state, including the Chicago collar counties. However, Simon received huge numbers out of the heavily populated and Democratic Cook County, which encompasses most of the Chicago Metropolitan Area. Percy led early on and well into the night, but as Cook County began to count all of its votes, Simon pulled ahead. Simon won despite then-president Reagan winning the state easily. Percy called Simon at around 5 A.M. the next day and conceded. Percy also congratulated Simon on his hard-earned victory. Simon was sworn in on January 3, 1985, and served in the senate until January 3, 1997, when he retired. Simon was later succeeded by Dick Durbin, a close friend and fellow Democrat.

Iowa

Incumbent Republican Roger Jepsen ran for re-election to a second term in the United States Senate. Jepsen was opposed by United States Congressman Tom Harkin, from Iowa's 5th congressional district, who won the Democratic primary uncontested. The general election was full of mudslinging and personal attacks, including the embellishment by both candidates of their military records; Harkin attacked Jepsen for failing to keep his promise to not sell AWACS aircraft to Saudi Arabia. Ultimately, Harkin defeated Jepsen by a wide margin, winning the first of five terms in the Senate.

Kansas

Incumbent Republican Nancy Kassebaum won re-election to a second term over Democrat James R. Maher, a financial consultant.

Kentucky

Incumbent Democrat Walter Huddleston ran for re-election to a third term, but lost by less than 0.5% to Jefferson County Executive Mitch McConnell.

Huddleston was unopposed in the Democratic Party's primary.

Louisiana

Incumbent Democratic J. Bennett Johnston won unopposed to a third term.

Maine

Incumbent Republican William Cohen won re-election to a second term over Democrat Libby Mitchell, State Representative.

Massachusetts

The election was won by Democrat John Kerry, the Lieutenant Governor of Massachusetts who remained Senator until 2013 when he resigned to become U.S. Secretary of State. One-term incumbent Paul Tsongas declined to seek re-election and retired from the Senate following a battle with cancer.

Michigan

Incumbent Democrat Carl Levin won re-election to a second term.

Minnesota

Incumbent Republican Rudy Boschwitz defeated Democratic challenger Joan Growe, Minnesota Secretary of State.

Mississippi

Incumbent Republican Thad Cochran won re-election to a second term over former Democratic Governor William Winter.

Montana

Incumbent Max Baucus ran for re-election. He easily won renomination in the Democratic primary, and advanced to the general election, where he faced Chuck Cozzens, a former State Representative and the Republican nominee. Despite President Ronald Reagan's strong performance in the state that year, Baucus was able to easily win a second term over Cozzens.

Nebraska

Incumbent Democrat J. James Exon won re-election to a second term over Republican businesswoman Nancy Hoch.

New Hampshire

Incumbent Republican Gordon J. Humphrey won re-election to a second term over Democratic U.S. Representative Norman D'Amours.

New Jersey

Incumbent Democrat Bill Bradley ran for re-election to a second term, defeating Republican Mayor of Montclair Mary V. Mochary.

New Mexico

Incumbent Republican Pete Domenici ran for re-election to a third term, defeating Democrat Judith Pratt.

North Carolina

The election was fought between the Republican incumbent Jesse Helms and Democratic Governor Jim Hunt. Helms won the election, the most expensive non-presidential election in United States history up to that point, by a margin significantly reduced from that that Helms achieved in 1978.

Hunt had a commanding lead in opinion polls for much of the campaign, with one poll in 1983 putting him nineteen points clear of Helms. However, that was changed by the most bitterly contested election in the country that year. Hunt ran a campaign ad connecting Helms to death squads in El Salvador through his association with the Nationalist Republican Alliance, for whom Roberto d'Aubuisson had recently run for the President of El Salvador. In the short time before election day, however, the highly popular incumbent US President Ronald Reagan gave Helms a significant boosthttp://www.unctv.org/U.S. Senatorno/peopleevents/events1.html by campaigning for him and running a local TV ad praising Helms and asking registered voters in North Carolina to re-elect him.

The election cost a total of $26,379,483 in total reported spending (over twelve times as much as the 1980 race), of which, 64% ($16.9m) was spent by Helms.