If the Tampa had occurred in 2001, but not September 11, other issues, such as the economy, health and education, would probably have appealed to people in the lead-up to the election more than boats. Labor could have recovered to an election-winning position. September 11 made national security a huge asset for the Coalition government at the 2001 election.
If not for September 11, Labor may have won the 2001 election. The Tampa put the Coalition into a tie with Labor, not a lead.