With Stapleton not running for reelection as Secretary of State of Montana in the
2020 elections, Jacobsen announced her candidacy. In the
Republican Party primary election, she defeated fellow Republicans
Forrest Mandeville,
Scott Sales, and
Brad Johnson. She defeated
Bryce Bennett, the
Democratic Party nominee, in the general election. Jacobsen was sworn into office on January 4, 2021. Shortly thereafter, she expressed her support for Republican legislation to end
same-day voter registration in Montana for all except military and overseas voters. In April 2021, Governor Greg Gianforte signed into law these restrictions; among the new restrictions was the end of
same-day voter registration in Montana, as well prevention of university students from using a
student ID as a
voter ID to vote. The new restrictions also limited ballot collection, which complicated voting in communities where election infrastructure was limited, such as the Native American community in Montana, a Democratic-leaning constituency. Jacobsen announced she was seeking reelection as Secretary of State in November 2023.
Jesse Mullen was the only other announced candidate. Jacobsen won a second term in the November 2024 elections. ==U.S. House campaign==