—Earned the backing of fellow anti-LGBTQ Missourian Sen. Josh Hawley for her primary campaign for the open U.S. Senate seat in that state.
—Created and appears in inaccurate and transphobic campaign ad for her U.S. Senate primary campaign in Missouri, attacking transgender athletes, specifically University of Pennsylvania swimmer Lia Thomas whom Hartzler deadnamed (the inaccurate and harmful use of a transgender person’s birth name, without their permission and with intent to harm/demean- content that is banned and removed on Twitter and TikTok). In the 30-second ad, Hartzler says, “Women’s sports are for women, not men pretending to be women.” Hartzler neglected to note that Thomas followed all guidelines to be eligible to compete, and has been cleared by the NCAA to compete in the March championships. Thomas’s teammates issued a statement of support on February 1, expressing “full support for Lia in her transition” and said they “value her as a person, teammate, and friend.” Thomas’ school has supported her inclusion on the women’s team, stating she “met or exceeded all NCAA protocols” established years earlier for athletes like Thomas.
—Scored a zero rating on The Human Rights Campaign’s Congressional Scorecard for the 112th, 113th, 114th, 115th, and 116th Congresses.
—Voted against the reauthorization of the Violence Against Women Act in 2019 because it required prisons house transgender people in facilities for people of their gender. “VAWA has become a partisan bill hijacked by liberals with a political agenda, who seek to elevate transgender politics over the safety and well-being of women,” she said in a statement released that year.
—Opposed the Equality Act, legislation to codify federal nondiscrimination protections for LGBTQ people in health care, housing, education, and other areas, falsely claiming, “This bill should be renamed the ‘Inequality Act,’ as its policies on the state level have already been used to eliminate safe spaces for women, irreparably harm children, trample parental rights, and undermine the free exercise of religion, and dismantle female athletics.” Hartzler also wrote in an opinion piece in The Hill that “The future of women’s rights, privacy, protection and athletic potential depends on” defeating The Equality Act.
—Coauthored a document which encouraged members of the Republican Study Committee to pressure Amazon to sell books promoting the debunked and dangerous practice of “conversion therapy” after Amazon said would no longer carry titles by Joseph Nicolosi, an “ex-gay” activist from the discredited fringe organization, NARTH, the National Association for Research and Therapy of Homosexuality. Amazon removed books by Nicolosi, who is credited with originating the ineffective and harmful practice.
—Offered an amendment to the National Defense Authorization bill to ban access to transition-related healthcare for military service members and their families, one year after the ban on transgender servicemembers was lifted. Hartzler incorrectly stated that there is still a “lack of medical consensus on the effectiveness of gender transition treatments.” Every leading medical organization recognizes the medical necessity of treatments for gender dysphoria and endorses such treatments. The Hartzler Amendment narrowly failed.
—Pressured then-President Donald Trump to ban transgender troops from serving in the U.S. military. When he announced the ban on Twitter, Trump echoed Hartzler’s language in opposition to transgender troops citing cost concerns. Hartzler offered, then rescinded, an amendment to block transgender troops during a House Armed Services committee meeting.
—Said young people should oppose marriage equality on the same grounds they oppose pedophilia and incest, saying, at the Eagle Forum Collegians 2011 Summit, “…If you just care about somebody and you have a committed relationship, why not allow one man and two women, or three women to marry?… Why not allow an uncle to marry his niece? Why not allow a 50-year-old man to marry a 12-year-old girl if they love each other and they’re committed?”
—Praised the passage of the anti-LGBTQ Proposition 8 in California, telling the St. Louis Post-Dispatch she was “glad,” and falsely claiming that gay rights issues aren’t civil rights issues. The “color of someone’s skin doesn’t change,” she said. She continued that there is debate about whether homosexuality is a “lifestyle or they were born that way.”
—Was a spokesperson for the Coalition to Protect Marriage in Missouri and advocated a successful state constitutional ban on marriage equality, the first of its kind in the nation, despite the fact that same-sex couples were not allowed to marry in the state at that time. The amendment passed but was voided by the U.S. Supreme Court decision in Obergefell v. Hodges that required the states to recognize same-sex marriage.