Presidents have displayed a tendency to declare more disasters in years when they face re-election. Mary W. Downton of the National Center for Atmospheric Research and Roger A. Pielke Jr. of the University of Colorado, Boulder, for example, looked at the flood-related disasters that were declared from 1965 to 1997 in an article published in "Natural Hazards Review" in 2001. Even after accounting for the amount of precipitation and flood damage each year, they found that the average number of flood-related disasters declared by the president was 46 percent higher in election years than in other years.

The tendency to declare more disasters during election years is not limited to floods. President Bill Clinton set a record by declaring 73 major disasters in 35 states and the District of Columbia in 1996, the year he was up for re-election.

When George W. Bush faced re-election in 2004, he declared 61 major disasters in 36 states - 10 more than in 2003 and tied for the second highest number of major disaster declarations ever, according to data provided by FEMA.

The increase from 2003 to 2004 was particularly sharp in the 12 battleground states in which the election was decided by 5 percent or less; these states had 17 major disasters declared in 2004 but only 8 in 2003, and, therefore, accounted for 90 percent of the increase.