NASHVILLE — Democrats say their presidential nominee, Barack Obama, can be competitive in Tennessee, but the most recent polling shows Republican John McCain’s widest lead in all 50 states can be found here.

According to an Aug. 20 survey of 500 likely Tennessee voters by independent pollster Rasmussen Reports, Sen. McCain, R-Ariz., has opened a 24-point lead on Sen. Obama, D-Ill.

Sen. McCain enjoyed a 56 percent to 32 percent edge in the poll, which had a 4.5 percent margin of error.

The closest comparable state, according to state-by-state surveys listed on the Web site RealClearPolitics, is Kansas. There, an Aug. 18-20 SurveyUSA poll of 641 likely Kansas voters found Sen. McCain ahead by 58 percent to 35 percent or 23 points.

The surveys were taken before the start of the Democratic and Republican national conventions. Republicans wrapped up their convention Thursday, a week after Democrats concluded theirs. The general election campaign, which culminates with the Nov. 4 elections, has now begun in earnest.

While Tennessee’s top Democrat, Gov. Phil Bredesen, has said repeatedly that the state is “tough” for Sen. Obama, state Democratic Party Chairman Gray Sasser said Sen. Obama’s Tennessee effort “is not an exercise in futility.”

“We’re a long way between now and Election Day,” Mr. Sasser said. “We realize it’s an uphill climb, but we’re ready to lace up our hiking boots and start hiking.”

Tennessee Republican Party Chairman Robin Smith, of Hixson, said before the convention, the GOP’s conservative base questioned whether it would give Sen. McCain a “bear hug or handshake.” Now, she said, newly energized Republicans are “definitely in a full bear hug.”

Sen. McCain’s choice of Alaska Gov. Sarah Palin, a social conservative, as his running mate will help him in Tennessee, Mrs. Smith said.

“I think you’re seeing that the values voters are coming over” to Sen. McCain, she said.

Democrats blame their nominee’s current poor showing in Tennessee on several factors, including Sen. Obama’s failure so far to campaign in the state or formally organize campaign support. Those are factors they hope will be corrected by the campaign’s move in late August to name a state director, Nashville attorney Jerry Martin.

Mr. Martin said the Obama campaign is “taking Tennessee very seriously” and will have paid campaign staff in Tennessee and likely have offices in major cities, including Chattanooga.

“Right now, the focus is on voter registration,” Mr. Martin said. “We’ve got six weeks to register, hopefully, 100,000 new voters. We’re going to get up every day from the crack of dawn until late at night making sure that anyone who is inclined to vote gets the opportunity to do so.”

Mr. Martin claims Democrats are a majority of the estimated 300,000 new voters who have registered in the state since August 2004.

In Tennessee’s 2004 election, President Bush defeated Democratic presidential candidate John Kerry by 1,384,375 to 1,036,477 votes (57 percent to 43 percent) or nearly 350,000 votes.

Two years ago in 2006, a nonpresidential election year, then-Republican U.S. Senate candidate Bob Corker defeated Democrat Harold Ford by 929,911 votes to 879,976 votes (51 percent to 48 percent), a difference of almost 50,000 votes.

Mr. Ford was the first black nominee of a major party in state history. Sen. Obama is the first black presidential nominee of a major party in U.S. history.

Tom Lee, a Nashville attorney who worked in Mr. Ford’s 2006 campaign, said he believes the Obama campaign “has suffered from the fact that they did not campaign here during the primary.”

He noted that then-U.S. Rep. Ford realized he was not well known outside his Memphis district and campaigned vigorously in areas such as East Tennessee. But doing that in a presidential campaign is difficult, where “demands on the campaign’s time and money are going to be enormous,” Mr. Lee noted.

As for race, Mr. Lee said Mr. Ford’s contest in 2006 “showed that Tennesseans are people who make judgments regardless of labels.”

“We are famous in this state for being independent-minded,” he said. “We’re ornery, even. Very few people are going to tell us how to vote based in the fact that we are of a particular race, party or gender.”