During the 2018 House of Representative elections Katie Hill defeated incumbent Representative Steve Knight. On April 10, 2019, Garcia announced that he would run in California's 25th congressional district against Hill in the 2020 House election. During his campaign announcement he stated that Hill was attempting to push a socialist agenda similar to Representative Alexandria Ocasio-Cortez. On October 27, Hill announced that she would resign from the House of Representatives due to a scandal involving her relationship with a campaign staffer, and resigned on November 3. On November 15, Governor Gavin Newsom issued a proclamation ordering a special election to fill the vacancy caused by Hill's resignation. On March 3, 2020, Garcia placed second in the nonpartisan blanket primary ahead of former Representative Steve Knight and behind Christy Smith, a member of the California State Assembly. On April 8, he was endorsed by the Club for Growth and the Susan B. Anthony List on April 24. On May 12, Garcia defeated Smith in the special election. She officially conceded the race the next day, but affirmed her intention to run against Garcia in the November general election for a full term in Congress. Garcia's victory marked the first time since 1998, when Doug Ose won in the 3rd congressional district, that a Republican flipped a California congressional district held by a Democrat. He is also the first Hispanic Republican representative to serve from California since Romualdo Pacheco left office in 1883, after representing the 4th congressional district.
Garcia is pro-life, and does not support the federal funding of Planned Parenthood. After winning the special election, Garcia signed a petition to bring the Born-Alive Abortion Survivors Protection Act to the floor of the House of Representatives for a vote.
Budget
While Garcia has stated that he supports Social Security, he does not support the expansion of federal funding for Social Security or Medicare.
Defense
Garcia supports the expansion of federal funding for defense programs. Garcia suggested increasing the United States Department of Defense's budget.
Education
Garcia does not support the adoption of national education standards, and believes that education should be managed on a local level. He has also advocated for cutting funding to the United States Department of Education.
Garcia has advocated for repealing the Patient Protection and Affordable Care Act. During his campaign, Garcia stated that he "was not a fan of Medicaid" and only supports Medicare "at certain levels."
Immigration
Garcia supports the construction of a wall along the Mexico–United States border. Garcia also supports a "case-by-case" system for returning immigrants to their county of origin. Garcia is also in favor of increasing surveillance at the border.
COVID-19
During a virtual debate with Christy Smith prior to the special election, Garcia stated that financial aid to small businesses should be administered through cities and local chambers of commerce. In May 2020, Garcia and other Republicans sought to block a bill that would provide transparency on the allocation of funding through the Paycheck Protection Program. Garcia has called on the United States House Select Subcommittee on the Coronavirus Crisis to investigate California Governor Gavin Newsom's policy on nursing homes during the pandemic. Garcia, along with other Republican representatives, claimed that Newsom had ignored guidance provided by the Centers for Medicare & Medicaid Services.
