After Bethany Hall-Long was sworn in as Lieutenant Governor on January 17, 2017, she resigned from her seat in the Senate. Governor John Carney announced a special election to fill her vacancy to be held on February 25. In anticipation of Hall-Long's resignation, Democrats from the local 10th district committee had selected Hansen as their nominee in December. The election had more significance than the average state senate race and was received national attention. At the time, the 21-member Delaware Senate was split evenly between 10 Democrats and 10 Republicans. While Democrats remained in control with the tie-breaking vote of Lieutenant Governor Hall-Long as senate president, a Republican victory would have given Republicans control of the chamber for the first time in over four decades, ending the complete Democratic control of the General Assembly. On a national level, the race was one of the first since Donald Trump took office and was described as important in showing the strength of Democrats in "a traditional stronghold like Delaware." The race received a large amount of national attention for an off-year state election race, and Democrats were poised to spend a "record-shattering" $1 million. Hansen's campaign itself raised more than $300,000 over the course of three weeks—six times that of her opponent—with money from across the country, including over 14,000 donations under $100. Former Vice President Joe Biden took a visible role in the campaign by fundraising, appearing in ads, and even going door-to-door with Hansen. Other prominent volunteers included Carney and former Maryland governor and 2016 Democratic presidential candidateMartin O'Malley. Hansen was also endorsed by the Delaware State AFL-CIO, the Delaware Building Trades, Delaware United, the Delaware State Education Association, the District Council of Delaware Laborers, Mary Ann's List, and the Barbara Gittings Delaware Stonewall Democrats. Her campaign focused on a multitude of issues including the cost of living for seniors, the opioid addiction epidemic, and affordable college education. Her campaign manager, Erik Schramm, emphasized the effort to "highlight local issues while harnessing the national mood to excite volunteers." As Hansen said that many of the voters she met while going door-to-door were watching television coverage of the protests against the new administration when she came to their homes. While special elections usually see lower voter participation, the turnout on election day was over 35%, higher than the 2014 midterm election. Hansen won with 7,315 votes against Republican nominee John Marino and Libertarian nominee Joseph Lanzendorfer. Democrats nationwide celebrated the victory as a big win for a new generation of activists after the election of Trump as president.