[2][3] Blunt Rochester began her political career working for Tom Carper, first in the House of Representatives, and later as he became governor of Delaware.

In 2023, Blunt Rochester announced her candidacy to represent Delaware in the United States Senate in the 2024 election and succeed the retiring Carper, who endorsed her in the race.

[4][5] She won the Democratic primary unopposed and defeated Republican nominee Eric Hansen by a landslide in the general election.

Governor Ruth Ann Minner named Blunt Rochester the state personnel director in 2001.

[2] In 2004, Blunt Rochester left government service and became the CEO of the Metropolitan Wilmington Urban League.

[2][7] Blunt Rochester ran for the United States House of Representatives in Delaware's at-large congressional district in the 2016 election.

[11] She won the Democratic Party nomination on September 13 with 44% of the vote in a five-candidate primary, defeating State Senator Bryan Townsend and venture capital firm owner Sean Barney.

[14] During the 2021 storming of the United States Capitol, Blunt Rochester was ushered into a secure room with fellow members of Congress.

[16] As of 2022, Blunt Rochester had voted with President Joe Biden's stated position 100% of the time, according to FiveThirtyEight.

[24] At the end of April, Blunt Rochester was named a member of the vetting committee for Biden's vice presidential candidate selection.

[26] For the 118th Congress:[27] On June 21, 2023, Blunt Rochester announced her candidacy for the United States Senate in the 2024 election to succeed Tom Carper.