The 28-year-old Wilmington native announced Tuesday morning she will try to replace Sen. Harris McDowell, D-Wilmington North, who is retiring at the end of his term.
McBride rose to national prominence in 2016 when she became the first openly transgender person to speak at the Democratic National Convention.
Long involved in politics, she is the national press secretary for the Human Rights Campaign, the largest LGBTQ civil rights advocacy group in the U.S. She plans to stay in that position part-time during her campaign, but would leave to be a full-time legislator if she wins, she said.
McBride first made headlines in 2012, when she came out publicly as transgender at the end of her term as American University student body president.
A transgender person identifies as a different gender than the one they were identified as having at birth. For example, someone who was born female but identifies as a man would qualify as transgender man.
Transgender lawmakers have been elected to other state legislatures, including Virginia's, in recent years.
"I don't intend on serving as a transgender state senator," McBride said. "I intend on serving as a senator who happens to be transgender."
McBride has previously worked for former Gov. Jack Markell and the late Attorney General Beau Biden.
For many in Legislative Hall, McBride is a familiar face. She advocated for passage of the Gender Identity Nondiscrimination Act, which Markell signed into law in 2013.
She's recently rallied with the local branch of Moms Demand Action, a group pushing for stricter gun laws in Delaware in the wake of mass shootings across the country.
Her Senate bid will likely focus on issues such as health care, paid family leave and criminal justice reform.
"Policies that impact people the most are handled at the state level," McBride told The News Journal. "That's where I believe I can make the most difference.
McDowell is retiring after more than four decades of lawmaking.