Des Moines, Iowa ? For Republicans here, the ideal presidential candidate would blend Ron Paul’s ideological passion with Mitt Romney’s electability. Newt Gingrich’s intelligence with Rick Perry’s evangelical appeal. Add a dash of social conservatism from Michele Bachmann and Rick Santorum — and stir.

Yet, as Lila Reynolds, one of many undecided Iowa Republicans, laments: “There is no Prince Charming.”

“What am I looking for?” Reynolds, 44, said, as she crammed into LJs Neighborhood Bar and Grill in Waterloo to see Gingrich ahead of Tuesday’s caucuses. “It’s hard to describe, but you know it when you see it.”

The “it’ factor was large in people’s minds as they sifted through their choices in the final hours before Iowa becomes the first state in the nation to have a formal say in picking a Republican challenger to face President Barack Obama next fall.

Interviews with more than three dozen Iowa voters in recent days found a restless GOP electorate, with many still up for grabs. A bunch seemed to be struggling with exactly what they wanted, not just from a particular candidate but from the heart and soul of a Republican Party fractured between tea party activists, evangelical Christians and mainline fiscal conservatives.

No single candidate has brought those threads together in voters’ minds.

“They’re all a little wobbly on the issues,” says Clara McKee, a 69-year-old from Emerson who plans to attend her first Republican caucuses. “None of them are perfect. None of them are exactly what I’m looking for.”

Her solution: “Go with the candidate who is the best package and will do the best job given the situation.” But she added: “I’m just not sure which of these candidates that is, though.”

For many people, no one seems quite right. And for a bunch, the process boils down to a hard choice between the safe, pragmatic candidate who stands the best chance of trouncing Obama or the fervent, ideological purist who sets the heart racing but is a far riskier bet in a general election.

They’re mulling these questions: Do they value electability more than anything else and buy Romney’s argument that he alone stands the best chance of defeating Obama? Or do they vote with their emotions and side with a candidate like Santorum considered a Republican who more closely advocates on their behalf on social issues? There’s a third option: stay home, frustrated at the prospect of nominating someone who doesn’t entirely fit the bill.

Just the other day, Grant Allen was struggling as he left a rally for Gingrich in Atlantic. He clutched a “Newt 2012” yard sign and mused: “Maybe I’ll actually put this one up.”

He said he was attracted to the former House speaker’s intelligence and bold ideas but not enough to sign on with him yet, saying: “I worry about the baggage, but he gave me some confidence today.”

Asked whom he would vote for, Allen grimaced: “Romney.”

The reluctance to back the former Massachusetts governor — and the search among conservative voters for someone other than him — is one of the defining themes of this Republican race. Romney, who lost the 2008 nomination to John McCain, doesn’t stoke the passions of conservatives who are skeptical about his Mormon faith and reversals on some social issues.

For months, Republicans here and nationally have rallied behind one alternative to him only to turn away and move on to another. Their flirtations have been brief in a race has seen no less than a half-dozen candidates at the front of the pack.

Muddling matters further has been a lack of consensus within the GOP about attributes the nominee must have.

Many tea party activists have tended to seek out tough-talking Republicans who will take it to Obama. Many cultural and religious conservatives crave a candidate who adheres strongly to their top issues, like opposition to abortion and gay rights. And a slew of establishment Republicans has hungered for a fiscal conservative who will reverse the bloat of the George W. Bush years.