A new Sachs/Mason-Dixon Florida Poll finds Barack Obama trailing Mitt Romney in America's biggest battleground and in a dead heat with Texas Gov. Rick Perry among Republicans.

"Unlike 2008, if the election were held today, President Obama would face a stiffer headwind to hold onto Florida and its 29 electoral votes against a top-tier Republican challenger - and that could cost him reelection," said Ron Sachs, President of Ron Sachs Communications. "Judging by the poll, President Obama's success in 2008 will be more difficult to duplicate in 2012. The Presidency will go to the candidate with the message that resonates with Florida's unique and diverse population and the resources to ensure that message is received by voters across the state."

Among the findings of the August Sachs/Mason-Dixon Florida Poll:

***51 percent of Floridians would vote for Governor Romney compared to 43 percent for President Obama;

***In a hypothetical matchup with Texas Governor Rick Perry, Perry leads with 46 percent to Obama's 45 percent;

***President Obama leads Congresswoman Michele Bachmann 46 percent to 44 percent; and

***41 percent of Floridians approve of President Obama's job performance while 56 percent disapprove. Fifty five percent of independents disapprove.

In April, a Sachs/Mason-Dixon poll found 51 percent of Floridians disapproving of President Obama's job performance.  In that poll, Governor Romney led President Obama in a hypothetical matchup with 48 percent for Romney and 43 percent for President Obama.

The August Sachs/Mason-Dixon Florida Poll also found Governor Romney leading all Republican hopefuls:

Mitt Romney   28%
Rick Perry   21%
Michelle Bachman  13%
Herman Cain   7%
Newt Gingrich  5%
Ron Paul   4%
Rick Santorum  2%
Jon Huntsman    -
Someone Else   3%
Undecided   17%

The April Sachs/Mason-Dixon poll found Governor Romney leading all GOP candidates with 23 percent of the vote.  In that poll, Romney led over candidates including former Arkansas Governor Mike Huckabee, billionaire Donald Trump and former House Speaker Newt Gingrich.

The Sachs/Mason-Dixon Poll was conducted by Mason-Dixon Polling & Research, Inc. of Washington, D.C. from August 18 through August 22, 2011. A total of 625 registered voters were interviewed statewide by telephone.  All stated they vote regularly in state elections. The margin of error is plus or minus 4 percent.

In addition, the survey also includes an over-sampling of 300 likely Republican primary voters for questions only on the GOP primary.The margin for error for the Republican primary voter sample is plus or minus 5.8 percent.