Robb later served as Democratic member of the
U.S. Senate from 1989 until 2001. Robb was elected in 1988, defeating
Maurice Dawkins with 71% of the vote. Robb ranked annually as one of the most ideologically centrist senators, and he often acted as a bridge between Democratic and
Republican members, preferring background deal-making to seeking the legislative limelight. His fellow Democrats removed him from the Budget Committee for advocating deeper cuts in federal spending. In
1991, he was one of a handful of Democratic senators to support authorizing the use of force to expel
Iraqi forces from
Kuwait. That same year he was one of only eleven Democrats to vote in favor of
Clarence Thomas's controversial nomination to the Supreme Court. In 1992 he was chairman of the Democratic Senatorial Campaign Committee, and during his term the DSCC raised record amounts of funding to elect seven new Democrats to the Senate.
On social issues though, Robb was more liberal. He voted for the
Assault Weapons Ban and against the execution of minors. He was opposed to a constitutional amendment to ban
flag burning. In 1993, he supported President Clinton's proposal to adopt the
Don't ask, don't tell policy on homosexuals in the armed forces. Three years later Robb was the only senator from a Southern state to oppose the
Defense of Marriage Act. In stating his opposition to the bill, which his friends and supporters urged him to support, he said the following: "I feel very strongly that this legislation is wrong. Despite its name, the Defense of Marriage Act does not defend marriage against some imminent, crippling effect. Although we have made huge strides in the struggle against discrimination based on gender, race, and religion, it is more difficult to see beyond our differences regarding sexual orientation. The fact that our hearts don't speak in the same way is not cause or justification to discriminate." Some have speculated that his position on gay rights, along with his positions on other hot-button issues like abortion, only alienated the generally conservative voters of Virginia, contributing to his eventual defeat.
In 1994, Robb narrowly defeated former
Iran-Contra figure
Oliver North in a poor year nationally for Democrats and despite being outspent 4 to 1.
Senator John Warner refused to support North and instead backed third-party candidate and former Virginia Attorney General
J. Marshall Coleman, whom Robb had defeated in the 1981 gubernatorial contest. The 1994 senate campaign was documented in the 1996 film
A Perfect Candidate. During the campaign, Robb won the endorsement of former Reagan Navy Secretary (and future U.S. senator from Virginia)
James Webb, and high profile Republicans such as Elliot Richardson, William Ruckelshaus, and William Colby.
Following his re-election in 1994, Robb continued to promote fiscal responsibility and a strong national defense; he was the only senate Democrat to vote for all items in the GOP's "
Contract with America" when they reached the Senate floor, including a
Balanced Budget Amendment and a
line item veto. He became the only senator to simultaneously serve on all three national security committees: Armed Services, Foreign Relations, and Intelligence. After two terms in the Senate and 25 years in statewide politics, he was defeated in a close race in 2000 by his Republican opponent,
George Allen, who was also a former governor. Robb was the only Democratic incumbent senator to be defeated in that election.