She gained national attention in 2014, when she delivered the Republican response to President Barack Obama's 2014 State of the Union Address.

[10] After completing her undergraduate education, McMorris was hired by state representative Bob Morton in 1991[11] as his campaign manager, and later as his legislative assistant.

[12] After being sworn into office on January 11, 1994,[11] she represented the 7th Legislative District (parts or all of Ferry, Lincoln, Okanogan, Pend Oreille, Spokane, and Stevens Counties).

[14][15] In 2001, she blocked legislation "to replace all references to 'Oriental' in state documents with 'Asian'", explaining, "I'm very reluctant to continue to focus on setting up different definitions in statute related to the various minority groups.

"[16] She voted against a 2004 bill to add sexual orientation to the state's anti-discrimination law, and was a vocal opponent of same-sex marriage.

[3] She is credited for sponsoring legislation to require the state reimburse rural hospitals for the cost of serving Medicaid patients, and for her work overcoming opposition in her own caucus to pass a controversial gas tax used to fund transportation improvements.

According to a Department of Energy study, retrofitting the largest 100 dams in the country could produce enough power for an additional 3.2 million homes.

[34] In January 2014, it was announced that McMorris Rodgers would give the Republican response to President Barack Obama's 2014 State of the Union Address.

[39] In 2014, the Office of Congressional Ethics recommended that the United States House Committee on Ethics initiate a probe into allegations by a former McMorris Rodgers staff member that McMorris Rodgers had improperly mixed campaign money and official funds to help win the 2012 GOP leadership race against Price.

[41] In 2014, McMorris Rodgers faced Democratic nominee Joe Pakootas, the first Native American candidate to run for Congress in Washington state.

[43] In 2018, McMorris Rodgers faced Democratic nominee Lisa Brown, a former majority leader of the state senate and former chancellor of WSU Spokane.

[55] In late 2013, she wrote a letter accusing Democrats of being "openly hostile to American values and the Constitution", and citing the Affordable Care Act and immigration as evidence that Obama "rule[s] by decree".

[57] McMorris Rodgers responded in 2014 to reports that Obama's program had provided coverage to over 600,000 Washington residents by acknowledging that the law's framework would probably remain, and that she favored reforms within its structure.

[58] In May 2017, she voted in favor of the American Health Care Act, a Republican health-care plan designed to repeal and replace large portions of the ACA.

[59] The bill would have eliminated the individual mandate, made large cuts to Medicaid, and allowed insurers to charge higher rates to people with preexisting conditions.

[66][better source needed] In 2015, McMorris Rodgers voted against upholding Obama's 2014 executive order banning federal contractors from making hiring decisions that discriminate based on sexual orientation or gender identity.

[69][70] The bill would prohibit "discrimination based on sex, sexual orientation, and gender identity in areas including public accommodations and facilities, education, federal funding, employment, housing, credit, and the jury system.

[75] In 2022 during the 2021–2022 Russo-Ukrainian crisis, McMorris Rodgers stated that she opposed sending American soldiers into Ukraine as a means to deter Russia.

[77][78] McMorris Rodgers voted in support of sending aid to Ukraine, Israel and Taiwan, a bipartisan effort bill aimed at helping U.S. allies[79] In 2022, McMorris Rodgers helped establish the bipartisan, bicameral Abraham Accords Caucus to support peace in the Middle East.

[83][84] McMorris Rodgers also repeatedly voted against the Rohrabacher–Farr amendment, legislation that limits the enforcement of federal law in states that have legalized medical cannabis.

[83][85] In 2018, McMorris Rodgers co-sponsored the STOP (Students, Teachers, and Officers Preventing) School Violence Act, which established a federal grant program to "provide $50 million a year for a new federal grant program to train students, teachers, and law enforcement on how to spot and report signs of gun violence", and authorize $25 million for new physical security measures in schools, such as "new locks, lights, metal detectors, and panic buttons".

[93] In December 2020, McMorris Rodgers was one of 126 Republican members of the House of Representatives to sign an amicus brief in support of Texas v. Pennsylvania, a lawsuit filed at the United States Supreme Court contesting the results of the 2020 presidential election, in which Joe Biden defeated[94] Trump.

The Supreme Court declined to hear the case on the basis that Texas lacked standing under Article III of the Constitution to challenge the results of an election held by another state.

[95][96][97] In January 2021, McMorris Rodgers announced her intention to object to the certification of the Electoral College results in Congress, citing allegations of fraud.

[98] She reversed her position after pro-Trump rioters stormed the United States Capitol, and said she would vote to certify Biden's win.

[99] She was the only member of Washington's congressional delegation to vote against the impeachment of Donald Trump for his actions stoking the January 6, 2021 assault on the Capitol.

[108] In 2024, McMorris Rodgers voted in favor of banning TikTok for their ties to the Communist China Party and posing as a national security threat.