In 2009, Fallon waged a grassroots campaign which netted him 57 percent of the vote to defeat three opponents for an at-large seat on the Frisco City Council. In the Denton County portion of Frisco, which consists of about one-third of the voters in House District 106, Fallon polled 65 percent of the vote. In his first year on the city council, Fallon voted against a tax rate increase. In 2010, he voted against a city budget that would have increased the municipal debt. In May 2011, his council colleagues chose him as Mayor Pro Tem. In 2012, Fallon easily won the Republican nomination in the reconfigured District 106 in which incumbent Republican Rodney Anderson of Grand Prairie did not run. Instead, Anderson waited two years and in 2014 unseated incumbent Republican Linda Harper-Brown in the primary election in neighboring District 105. To win his House nomination, Fallon defeated Amber Joelle Fulton, a former trustee of the Lewisville Independent School District, 5,806 to 2,333. Fulton proclaimed herself a "conservative" in the District 106 race. The year before, she unsuccessfully lobbied state legislators to gain approval for the school district to increase local taxes without the need for an election. Not long afterward, Fulton was defeated for reelection as a board trustee. Fallon won the general election on November 6, 2012, 41,785 against Libertarian Party nominee Rodney Caston's 8,455 votes. No Democrat sought the seat. Fallon was the co-author of a 2013 Texas law which allows students and employees of independent school districts to say, "Merry Christmas", rather than "Happy Holidays." Fallon ran unopposed for the Republican nomination in 2014 and defeated Democrat Lisa Osterholt and Libertarian Rodney Caston in the general election, winning 24,419 votes, almost 70 percent of the popular vote. In the 2016 Republican primary, Fallon defeated challenger Trent Trubenbach with 16,106 votes to Tubenbach's 3,327 votes. He went on to win the general election with 80.8 percent of the vote. In July 2017, Fallon announced that he would challenge incumbent state Senator Craig Estes for the Republican nomination in Senate District 30. Fallon defeated Estes and Nocona businessman Craig Carter in the primary on March 6, 2018, with 53,881 votes. In the ensuing general election on November 6, Fallon defeated the Bridgeport Democrat Kevin Lopez. With 233,949 votes, Fallon overwhelmed Lopez, who drew 82,449 votes. Fallon served on the House committees of Human Services and Technology.
Legislative positions
Fallon defended his "Merry Christmas" law in an appearance on David Barton's WallBuilders Liveradio program. Fallon told co-host Rick Green, a former member of the Texas House from Hays County in suburban Austin, that those offended by public schools hosting Christmas parties should examine their own hearts to evaluate their attitudes. Both Fallon and Green said that no citizen has a constitutional right "not to be offended" Fallon vowed to make T-shirts with a Christmas theme for pupils to wear on the day before the holiday break. A pro-life legislator, Fallon supported in 2013 the ban on abortion after twenty weeks of gestation; the measure passed the House, 96-49. He co-sponsored companion legislation to increase medical and licensing requirements of abortion providers, a measure which opponents claim will cause some abortion clinics in the state to close their doors. These issues brought forth an unsuccessful filibuster in the Texas State Senate by Wendy R. Davis of Fort Worth who in 2014 was the Democratic nominee for governor opposite the Republican Greg Abbott, the choice of Fallon. The TexasRight to Life Committee rated Fallon 100 percent favorable. Fallon opposed the bill to establish a taxpayer-funded breakfast program for public schools; the measure passed the House, 73-58. He co-sponsored legislation to provide marshals for school security as a separate law-enforcement entity. He co-sponsored the successful bill to extend the franchise tax exemption to certain small businesses. He voted to require testing for narcotics of those individuals receiving unemployment compensation. Fallon co-sponsored the measure to forbid the state from engaging in the enforcement of federal regulations of firearms. He co-sponsored legislation to allow college and university officials to carry concealed weapons on campus and in vehicles in the name of security. He voted to reduce the time required to obtain a concealed-carry permit. Fallon voted for term limits for certain state officials. To protect election integrity, Fallon supported legislation to forbid an individual from turning in multiple ballots.
