2018Final results
2018 election for U.S. Senate in Delaware
U.S. Senate · Delaware
Thomas R. Carper (D) won with 60.0% of the vote, defeating Robert B. Arlett (R) by 22.1 points.
Thomas R. CarperDemocrat · winner
60.0%217,385
Robert B. ArlettRepublican
37.8%137,127
1.1%4,170
Nadine M. FrostLibertarian
1.1%3,910
362,606 votes
Source: MIT Election Data and Science LabUpdated Oct 1, 2026, 6:17 AM ET
The seat over time
D − R margin in this seat's races around 2018
Races before and after
Source: MIT Election Data and Science LabUpdated Oct 1, 2026, 6:17 AM ET
Money in this race
Each line compares the two campaigns on one scale.
Thomas R. CarperRobert B. Arlett
$3.2M
Raised by the campaign
$225.8K
$3.1M
Spent by the campaign
$223.8K
$360.6K
Cash on hand
$2K
Campaign money: FEC, through Dec 31, 2018.
Source: FEC campaign filingsUpdated Dec 31, 2018
The candidates
Thomas R. Carper (D)Robert B. Arlett (R)
Also on the ballot: Demitri G. Theodoropoulos (Green), 1.1%; Nadine M. Frost (Libertarian), 1.1%