Republican Senate candidate Marco Rubio speaks to reporters after casting his ballot in Florida's primary election in Miami August 24, 2010. Credit: Reuters/Joe Skkipper

By Steve Holland

WASHINGTON |

WASHINGTON (Reuters) - Republican candidate Marco Rubio has opened a clear lead in a Florida Senate race, becoming the latest Tea Party favorite to benefit from voter anger at Washington, a Reuters/Ipsos poll found on Wednesday.

Six weeks before November 2 congressional elections, Rubio leads state Governor Charlie Crist, an independent, by 40 percent to 26 percent among likely voters, the poll found. Democrat Kendrick Meek trails at 21 percent.

The conservative Tea Party roiled Republican politics when a little-known candidate backed by the movement beat a veteran lawmaker in Delaware on Tuesday in the race to decide the Republican nominee for U.S. Senate in November.

The Tea Party is a loose-knit group of mostly Republicans that has been attracting anti-Washington voters upset at government spending, taxes and deficits. They are strong critics of President Barack Obama.

Tea Party-backed candidates have ousted Republican establishment politicians in Nevada, Colorado, Kentucky and Connecticut. Crist fled the Republican Party earlier this year to run as an independent when it seemed clear he would lose to the conservative Rubio in the state's primary vote.

Rubio, the son of Cuban immigrants, is softening his rhetoric in an apparent attempt to appeal to moderates before the November vote.

"The language he is using is a little more mainstream Republican," said Ipsos pollster Julia Clark.

The poll numbers show a big swing since mid-August, when an Ipsos Public Affairs poll showed Crist leading Rubio by 33 percent to 29 percent if Meek were the Democratic candidate.

Florida is one of a dozen toss-up Senate contests across the United States that could decide the balance of power in the November and the fate of Obama's legislative agenda.

Voters are anxious about high unemployment and the sour economy in this election year when all 435 seats of the House of Representatives are up for grabs in November along with 37 Senate seats and 36 governorships.

ENTHUSIASM GAP

Florida, like other states, has a large "enthusiasm gap" with Republicans far more motivated to vote in November than Democrats. The poll said 82 percent of Republicans said they are certain to vote, compared to 61 percent of Democrats.

Crist and Meek are likely splitting Democratic votes, according to the poll.

When voters were asked their choice between Rubio and Crist if Meek was not in the race, the contest is essentially tied -- Rubio 46 percent, and Crist 45 percent.

"We know that until recently Crist has been benefiting tremendously from Democratic support and that seems to have ceded somewhat," Clark said.

Concern among Floridians about the economy has increased 10 points since the last poll in early July -- 61 percent said the economy is the biggest problem facing the state, up from 51 percent.

This could be related to declining concern about the BP Plc oil spill that afflicted the Gulf and damaged Florida tourism, Clark said.

Crist still has strong job approval ratings as Florida governor, with a majority of Floridians saying they approve of the way he is handling his job.

But he will also have to contend with an anti-incumbent mood. The poll said he is seen as more likely than Rubio to "say anything to win votes" and more "part of the problem with politics right now in this country."

The race to replace Crist as governor is close, with Republican Rick Scott and Democrat Alex Sink statistically tied, Scott with 47 percent and Sink with 45 percent, the poll found.

The survey of 600 registered Florida voters, of which 486 said they are likely to vote has a margin of error of plus or minus 4 percentage points among registered voters and 4.6 points among likely voters.

(Additional reporting by Alistair Bell; Editing by Doina Chiacu)