One week after keynoting the Tea Party convention in Nashville, Sarah Palin attended NASCAR's premiere race – the Daytona 500. "It's an all-Americana event," she said in a brief speech. "We love you, Sarah!" fans shouted on her way out. The next day she visited the local Chamber of Commerce and signed copies of her bestselling book, "Going Rogue."

This is how presidential hopefuls test waters. Daytona Beach falls at the eastern edge of Florida's I-4 corridor. It's the swing region in this key swing state. Palin has already acknowledged she's considering a run. And no less than the dean of the Washington press corps, David Broder, wrote last week "Palin is by all odds a threat to the more uptight Republican aspirants such as Mitt Romney and Tim Pawlenty" and "potentially" Barack Obama.

But Palin, by any empirical measure, deserves long odds. The 2012 cycle might be Palin's big chance at the big show. She is still fresh off a sellout book tour that, brilliantly, amounted to an old-fashioned barnstorm. Yet the hyper-coverage, the passionate supporters and obsessive detractors, obscure one clear fact: Americans are losing respect for Palin.

Palin's goal after the 2008 campaign was to prove she had the substance to match her exceptional talent. But today fewer view Palin as presidential than on Election Day '08. Then, according to exit polls, 38 percent of voters saw her as qualified to be president.

Now, 26 percent view her as qualified, according to last week's ABC News/Washington Post poll. Polls have echoed this result for months. Compared to Palin, CNN found late last year, three times as many voters say Hillary Clinton is qualified. Twice as many say the same about Joe Biden. Palin's potential competition, Mike Huckabee and Mitt Romney, rate in the 40s.

Palin has problems even by a political upstart's standards. Consider John Edwards vintage 2004. That July, when Edwards was tapped as the vice presidential nominee, Gallup found that 57 percent saw him as qualified.

It's an analogy the Palin camp detests. But the more accurate comparison is to Dan Quayle. Only one third of adults thought Quayle was qualified to be president in March and November 1990, a comparable period in the presidential cycle.

And Palin has her own team to blame. One in four Republicans viewed Palin as unqualified on Election Day. That figure has now doubled to 52 percent in the ABC/Post poll.

Palin's poor standing with independents is even more troublesome. Two-thirds of independents view her as unqualified. That is a "very big number," Karlyn Bowman said, a public opinion specialist at the American Enterprise Institute.

On Palin's prospects, Bowman notes the indisputable: "Palin is in a very strong position in the Republican field today."

But can she go all the way?

"It's a very steep climb," Bowman replied, "if her negatives are what they are now, you have to be able to win independents."

This is the cold irony of Palin's star. Palin is losing stature with the very voters she champions: regular Americans who vote Republican.

The atmospherics of the next presidential campaign do suit Palin. It's a cycle for outsider candidates. It will be more of a base election than 2008. Yet here too Palin will face obstacles.

George W. Bush's 2004 campaign was a textbook base strategy. Yet he did not have to compensate for weaknesses with the center. He only had to win a small slice of it. W began 2004 with 65 percent of Americans having a "favorable" view of him, according to Gallup.

Only 37 percent of the public has a favorable opinion of Palin, according to the ABC/Post poll. Her personal appeal, once her asset, is now too an issue.

Remember the question that once dogged Hillary Clinton: was she "too polarizing" to be president? Innumerable Republicans argued yes. Even Obama later implied so much. At the time, 2005 and 2006, Clinton's favorability ratings were in the low to mid 50s.

Plainly put, Palin today faces the worst hurdles of both Clinton and Quayle combined.

Palin has some reason for optimism. Qualifications do not win presidencies. But every contender must pass the gut check, prove able and ready. And so will Palin.

Obama had to prove himself qualified. But the public's first impression of Obama was stronger than it was with Palin. It also strengthened over time. A Fox News poll found in February 2007, when voters were just meeting Obama, that 52 percent of adults thought he was "very" or at least "somewhat" qualified to be president. That view of Obama improved about 10-percentage points by autumn.

That means Obama came into the race with about twice Palin's qualification standing. And Clinton came into the race with a favorability rating at least a dozen points above Palin's.

Palin needs a rebranding. Not since the "New Nixon" has it been done. And that was the dawn of the televised presidency. Perceptions might harden far sooner in this hyper-media era.

Palin's believers remain as dedicated as ever. Millions still echo the chant: "Run, Sarah, run." But most Americans do not agree.

A mid-January CBS News poll found that only one fifth of adults would "like to see Sarah Palin run for president." That includes only a quarter of independents and slightly less than a third of Republicans. Fully 58 percent of conservatives do not want Palin to run.

"Others in the party see a path of victory for her and frankly, I'm not there at the moment," said GOP pollster Kellyanne Conway. "It currently is possible, but improbable."

Here's how the improbable could still come about: First, she is able to win back those she's lost since the campaign. The other major Republican candidates pull their punches for fear of a backlash from the party base. The GOP contenders turn out to be conventional duds in a year of feverish anti-Washington and anti-establishment passion. Republicans divide. And with heavy lifting by social conservatives – about six in ten GOP voters are white evangelicals in Iowa and South Carolina – Palin's supporters propel her to the general election.

Meanwhile, in this hypothetical, Obama's first term finishes like George H.W. Bush or Jimmy Carter. Obama's team decides to ignore campaign history – Stevenson vs Ike, Carter vs Reagan and Gore/Kerry vs W – and tries to paint Palin as too dumb to be president. The media continues to over-cover mundane acts like writing notes on your hand. Her base becomes more inspired by each unfair incident. Soon Palin disciplines. She overcomes polarization barriers not even Hillary Clinton encountered. And there she stands. The two debate. She proves herself Obama's equal. Sure, it's possible. But remove any piece and the Palin presidency tumbles.

Reelections are referendums on the incumbent. However, the alternative matters. Imagine if H.W. Bush beat Reagan in the 1980 primary. Carter would have likely pulled out a second term.

Strategist Ed Rollins, once an advisor to Reagan, warns that one should still not make light of Palin. "I've seen too much of this business to underestimate anybody," he said. "She has the most valuable asset that any politician can have, which is name ID. I think the potential is there for her to be a star again."

Republicans though rarely go with the insurgent star. The last movement candidate to win the GOP nomination was Barry Goldwater. Insurgent Reagan lost in 1976. Establishment Reagan – well, ask Carter how that went. Bill Clinton's line rings true even in an anti-Washington year: "In every presidential election, Democrats want to fall in love; Republicans just fall in line."

There are other issues as well. GOP players complain that Palin's staff is inaccessible. She is only minimally campaigning for her fellow Republicans.

And then there is the learning curve on big issues. Last week Palin spoke cavalierly on Fox News about Iran, perhaps the most fraught national security issue of the day. Palin posited that if "say, [Obama] played the war card" on Iran, it would change the political landscape. Former Vice President Dick Cheney rebuked her Sunday on ABC News: "I don't think a president can make a judgment like that on the basis of politics. Stakes are too high." This is why even sympathetic conservatives, who hold her in great esteem, question whether Palin can pull it off.

"She can be a serious contender," said Richard Land, a longtime social conservative leader. "I think Sarah Palin will decide that for us, between what she does now and the winter of 2011. The presidential nomination process is a brutal process," he added, "and it does serve certain purposes. It whittles out those who aren't up to the snuff."