They're the most fickle voters, and potentially the most powerful. Thus, with party nominations secure, John McCain and Barack Obama now are pushing toward the center to win them over.
Meet the "mushy middle," a complex chunk of people likely to decide the presidential election but difficult to reach and hard to please.
"Yes, we can!" isn't floating their boat. Nothing much is, from either candidate.
They aren't uniformly conservative or liberal, and they don't fit strict Republican or Democratic orthodoxy. They aren't typically engaged in politics, and they don't much care about the campaign. And like so many others, they are extraordinarily pessimistic.
"To me, it's not about the party, it's about who is the best person for the job," says Pam Robinett, 47, from Wellington, Kan., who always votes. Then again, "they'll all lie, cheat and steal to get what they want."
Talk about a tough sell.
"The country's going to go to hell in a handbasket with this election," seethes James Nauman, 55, from Lutz, Fla. "I don't think Obama's qualified and McCain's another Bush. Neither of them really have impressed me."
Both will try.
Trying to appeal to the middle
A recent AP-Yahoo News poll finds that 15 percent call themselves moderates and aren't solidly supporting a candidate. More than half of this still-persuadable middle is made up of independents.
"The center always matters," said Andrew Kohut, director of the Pew Research Center. "It matters more this year. Both candidates were nominated because they appealed to independents and moderates, so how these voters make a choice between Obama and McCain will be even more decisive."
For now, at least, the race is competitive and the rivals' bases are mostly intact.
The survey, conducted by Knowledge Networks, found that three in four Republicans and three in four conservatives are backing McCain, while Obama has nearly identical support among Democrats and liberals.
So, both are tacking away from their party's ideological ends to appeal to this unpredictable swath in between.
McCain is moving away from the unpopular President Bush if not from the Republican Party itself. He emphasizes bipartisanship while pressing two issues that resonate strongly with voters of all stripes.
He "stood up to the president and sounded the alarm on global warming," one McCain commercial says. Another promotes a "bipartisan plan to lower prices at the pump, reduce dependence on foreign oil through domestic drilling and champion energy alternatives."
Obama, for his part, broke from the left by backing new rules for the government's terrorist eavesdropping program, straddling a Supreme Court ruling striking down a gun ban and objecting to the justices' decision outlawing executions of child rapists. He even quoted conservative hero Ronald Reagan's "trust but verify" line in reacting to North Korea's latest agreement on nuclear weapons.
His leadoff campaign commercial cast him as the embodiment of the center and pitched family values, patriotism, "welfare to work" and lower taxes. It stressed "love of country" and "working hard without making excuses" — echoes of Bill Clinton.
McCain naturally may be better positioned to capture more of the middle; he came out of the GOP's center to dispatch liberal Rudy Giuliani on his left and conservative Mitt Romney and Christian evangelical Mike Huckabee on his right. Obama emerged from the party's left to topple the more centrist Hillary Rodham Clinton.
However, Obama and McCain both won their nominations with the support of independents, moderates and crossovers from the opposite party.
Some 39 percent of voters called themselves Democratic, 29 percent Republican, and 32 percent independent in the June 13-23 survey, part of an ongoing study tracking opinions of the same group of people over the election cycle. The overall margin of sampling error was plus or minus 2.3 percentage points.
That Democratic edge suggests Obama may be less dependent on votes in the middle than McCain.
Still, the likeliest path to the White House cuts through the center of the electorate.
"They're the kingmakers in American politics," said Matt Bennett, a Democratic operative at the centrist Third Way policy group. "They're the people who decide elections."
Who exactly are these power-wielding voters?
They look much like the general population. They reflect the same frustration with the status quo. A significant majority has a low opinion of Bush and Congress. They have more favorable impressions of Democrats than Republicans. Many are feeling the economic pinch. They want troops to return from Iraq as soon as possible.
Like the broad electorate, they rank gas prices and the economy as their top concerns, followed by health care, Social Security, taxes and education. Terrorism and Iraq are lower.
But there are important differences.
Compared with far-right and far-left voters, this group tends to be more Hispanic, more Catholic than the left and more secular than the right. They are more likely to be married with children and live in far-flung suburbs or rural areas. They also tend to be less educated.
They are not nearly as motivated as those who identify with political parties or ideologies. Fewer are registered to vote.
"These are the most disengaged voters," said Ron Shaiko, a public policy specialist at Dartmouth College. "There's a point at which they're going to engage, and it's not clear who will win when they do."
Nearly half view McCain favorably, while slightly more than a third see Obama positively. Still, the candidates are little-known to a quarter, and many have little enthusiasm for either.
"I like McCain more because I'm concerned about Obama. I question his judgments," says Tony Miller, 39 and a left-leaning moderate from Springfield, Ill. Conversely, Susan Carroll, 43, a moderate Democrat from Garrettsville, Ohio, says Obama's "the better choice" because "I honestly think that McCain is anti-woman."
"Bread-and-butter" issues most important
This voting group's views cross some of the usual lines.
For instance, they overwhelmingly favor abortion rights and legal rights for same-sex couples, typically Democratic and liberal positions. But they also overwhelmingly say cutting taxes should be a high priority, typically a Republican and conservative refrain.
These voters say they are far less interested in cultural issues and far more interested in bread-and-butter subjects like health care and Social Security.
"The center of the American electorate — moderates, independents and ticket splitters — is an amalgam of disparate interests with the following commonality: all are a few points from the ideological center of the country, and they tend to be fiscally conservative and socially tolerant," said Greg Strimple, a Republican pollster in New York.
Take Jan Thomas.
"I'm liberal in some areas and I'm conservative in others," says the undecided moderate from Stevensville, Mont., who is 69 and shuns party labels.
Unlike the GOP, she supports abortion rights and declares "to each his own" on gay marriage. Splitting from the Democrats, she objects to "big government," costly entitlement programs that "lead to dependency" and universal health care proposals "that mean higher taxes."
She's unsettled about both candidates.
Obama's "inexperience and his voting record on gun control" bug her; she owns two handguns, a shotgun and a rifle and is still "a pretty good shot." She doesn't like McCain's "vacillating" or stances on the environment and comprehensive immigration reform. "I do not believe in global warming," she says. And "we've got to secure our borders."
David Donovan, 31, a GOP-leaning independent from Crystal River, Fla., also is "not exactly thrilled with either of them."
McCain on foreign policy "just doesn't make a lot of sense," but Obama's "abundance of gun control" irks this gun owner, as does the Democrats' education platform. And, he says, "I think taxes suck."
Not that he has time to follow the campaign closely; Donovan travels 150 miles roundtrip to build bridges for 14 hours a day. The commute costs his one-income household $50 in tolls and $220 in fuel each week. He and his wife haven't had health care coverage for two years. She's on disability after seven mild strokes. Her student loan debt is growing.
"There are some days where I'd vote for Mickey Mouse for president," Donovan said. "It's got to be better than this."