Gary L. Daniels graduated from Milford Area High School and earned a vocational degree from New Hampshire Technical Institute. He holds a Bachelor's Degree in Management and Information Systems from New Hampshire College. Daniels served in the United States Army, New Hampshire Army National Guard, and United States Army Reserve. He has held various roles, including serving on the Milford Board of Selectmen and in the New Hampshire House of Representatives and Senate. Daniels has also been a board member for Little Arrows Childcare Services and Granite State Taxpayers.

Gary L. Daniels champions a blend of fiscal conservatism with progressive social policies, advocating for tax cuts to stimulate economic growth while promoting increased funding for public schools and affordable higher education. Daniels's approach to environmental policy reveals a unique balance, emphasizing economic impacts alongside renewable energy incentives. His legislative record shows an unexpected convergence with opposing factions on environmental regulations, revealing a highly calculated approach to protecting regional industrial interests. Daniels's rhetoric consistently underscores family values and community, often framing issues in terms of their impact on local families and veteran welfare.