In 1991, Crosby became state director for the Queensland division of the Liberal Party of Australia, and in 1994 the party's deputy federal director. He served under federal director Andrew Robb, until replacing him as federal director of the Liberal Party in May 1997. Crosby served as campaign director for the party at the 1996, 1998, 2001, and 2004 federal elections. In 1998, the government won with marginal seats (swing seats) targeted by Crosby. The election saw the smallest two-party-preferred margin win since 1949 estimates, on 49.02 percent.