Independent Florida voters are on the verge of killing John McCain’s hopes for the presidency.

A new St. Petersburg Times/Bay News 9/Miami Herald poll shows Barack Obama leading McCain 49 percent to 42 percent in this state McCain cannot afford to lose. The biggest factor? Less partisan independent voters moving to Obama by a margin of more than 2 to 1.

"Right now this election is about independents — independents and the economy,’’ said pollster Tom Eldon. "Obama is clearly establishing himself as the candidate of the independents.’’

At a time when economic anxiety trumps all issues in Florida, about half of the voters surveyed — and almost 6 in 10 independents — said Obama has a better plan to improve the economy, while one in three voters say McCain does. Forty-five percent said Obama has shown the most leadership on the economy, and 34 percent said McCain.

“The predominant color in Florida right now is neither blue nor red, it’s green,” said pollster Kellyanne Conway. “The financial concerns, money concerns, dominate voters’ calculus.’’

Conway, who’s company works mostly with Republicans, questioned the effectiveness of McCain’s recent campaign strategy.

"Trying to connect Barack Obama to Bill Ayers, rather than connect McCain to the average voter in the economy has ... been dubious,’’ she said, referring to the 1960s radical Obama knows.

The telephone survey of 800 registered voters was conducted Oct. 20-22, for the Times, Bay News 9 and Miami Herald. The poll was done by Schroth Eldon & Associates, whose clients primarily are Democrats, and the Polling Co., which mainly works with Republicans. The margin of error was plus or minus 3.5 percentage points

It is virtually impossible for McCain to win the presidency without Florida’s 27 electoral votes, and the poll suggests Florida remains within reach for the Arizona senator.

Eldon noted that McCain needs to boost his lagging numbers in traditional Republican strongholds including southwest Florida, one of the most economically devastated areas of the state. Florida’s top battleground of Tampa Bay is predictably close with the poll showing Obama with 48 percent support and McCain with 44 percent, within the margin of error.

McCain leads Florida Hispanic voters 47 percent to 40 percent, while 86 percent of African-Americans back Obama. McCain leads 49 percent to 43 percent among white voters overall, but Obama has an 11-point lead among women and is nearly tied with McCain among men.

Among voters 65 and older, McCain and Obama are in a dead heat, with 11 percent still undecided.

"If there’s any more fluidness left in this race — and God knows there probably is because this is 2008 and nothing predictable — it may rest with these seniors,’’ said Conway.

Hundreds of thousands of voters already have voted in Florida, either by absentee ballot or at early voting sites, and McCain and Obama were tied among people who already had voted. Forty-four percent of those polled said they intended to vote on election day, 15 percent by mail, 37 percent at early voting sites.

So far, of the more than 800,000 people who have voted by absentee ballot, Republicans have an advantage of nearly 130,000. But of the more than 482,000 who voted early between Monday and Wednesday, 55 percent were Democrats and 30 percent Republican, a net advantage of 117,000 for Democrats.