After graduation, Baird pursued a career in finance and investments in Northwest Arkansas. He was a securities trader for Arvest Bank in Lowell, where he held both the Series 7 general securities license and the Series 66 state securities license.
As a 28-year-old political newcomer, Baird entered the Republican Primary for State Representative against Linda Bisbee, the wife of 14-year incumbent State Senator Dave Bisbee. Baird ran an aggressive grassroots campaign and defeated Bisbee by a margin of 1,598 to 1,435. He was unopposed in the November general election.
Baird is known for his knowledge of the state budget and his work on ethics and government reform. As a legislator, he followed a no-gift rule, refusing to take even a cup of coffee from a lobbyist. He worked to establish a cooling-off period before a legislator, constitutional officer, or state agency head could become a lobbyist. In addition to serving as chairman of the Joint Budget Committee, Baird was a member of the House committees on Revenue & Taxation and State Agencies & Governmental Affairs. Prior to the 2013 legislative session, Baird was named one of the "Top 10 Legislators To Watch" by . Baird served as a delegate to the 2012 Republican National Convention from Arkansas for Mitt Romney. He was a member of the Budget and Revenue Committee of the National Conference of State Legislatures. Grant Hodges of Rogers was the successful Republican nominee to succeed Baird in House District 96. In the May 2014 Republican primary, Rogers polled 1,392 votes to intraparty rival Damon Dale Wallace's 635 votes. Hodges then defeated Democratic and Libertarian opponents in the November 4 general election.
In 2013, Baird announce his candidacy for state treasurer, an office formerly held by the DemocratMartha Shoffner, who stepped down in 2013 amid charges of corruption and was replaced by the temporary appointee, Charles W. Robinson. "My primary focus as State Treasurer will be to restore trust to the office. I want the people of Arkansas to be able to look at the treasurer’s office and have confidence that we’re working on behalf of them to do what’s best for the state," said Baird in a statement of candidacy. Baird earned the endorsement of the statewide Arkansas Democrat-Gazette, which said, "Duncan Baird is the obvious choice in this Republican primary", as well as the Northwest Arkansas Newspapers. Conservative columnist Jason Tolbert endorsed Baird, saying, "In short, Baird is qualified, well-respected, understands state government, has the investment experience needed, and most importantly has the high ethical standards that inspire trust. He is clearly the man for such a time as this." He was also endorsed by the National Rifle AssociationPolitical Victory Fund, which gave him an "A" rating for his support of the 2nd Amendment, and he received a 100% rating from the National Federation of Independent Business for his votes on small business issues. Baird was defeated by Dennis Milligan, 53-47 percent, in the Republican primary election on May 20, 2014.
