NEW PORT RICHEY, Fla.  Jim Piccillo lost his job at a bank in August, applied for food stamps to support his two young daughters and swore off a life of loyalty to the Republican Party. He now volunteers here in Pasco County for Senator Barack Obama of Illinois.

Madeline Aquanno’s change of heart came more recently. Two weeks ago, she said, she had planned to vote for Senator John McCain of Arizona, the Republican, who impressed her with his knowledge of the world. But as the economy began to scare her more than terrorism, she reconsidered.

“Obama is more for the people,” she said, near the pool at her middle-class retirement community in Broward County. “I’m worried about the jobs that are being lost, for my son, my daughter, my granddaughter. You have to look down the line.”

Here in a swing state of severe economic hurt  a leader in foreclosures where empty offices now litter strip malls  there are signs that Mr. Obama is gaining ground. In interviews and surveys, voters across Florida said the debate in Washington over how to fix the credit crisis had fueled frustration with the Bush administration and pushed them away from the Republican ticket.