Salena Zito

CARROLL, Iowa -- The race is down to the wire and is still hard to call.

When Iowa Republicans caucus with their neighbors on Tuesday. night, they will have scrutinized the presidential candidates more closely than ever before.

"This is a head, not a heart, election. Voters are very serious this year, and they should be; there is a lot at stake in this country," former House Speaker Newt Gingrich told the Tribune-Review after an event at Santa Maria Winery in this West Central Iowa city.

Experts predict he will take fifth place or worse.

"We want to make sure that who we send into the general election next year is seasoned and ready to take on President Obama," said Ben Puck, a businessman who will caucus at Carroll's community center. Puck, 53, said he respects and admires Gingrich as a conservative thinker but does not think he has the basic understanding of economics to run the country.

In the final push to earn votes this week, candidates used old-fashioned politicking: barnstorming across the state in buses bearing their shrink-wrapped likenesses and slogans. As they shook hands and posed for photographs, they often took tough questions from people about how they could offer an effective alternative to Obama's policies.

Appearing confident and competent, former Massachusetts governor Mitt Romney leads most polls.

"No thing is a sure thing at this stage, but it feels terrific," he said on Friday after appearing with New Jersey Gov. Chris Christie at an event outside a grocery store near Des Moines.

"The governor has always been respected here," said Steve Lewandowski, 52, of Dubuque, a businessman who earlier in the week drove 74 miles to hear Romney speak in Davenport. "While all of the other candidates rose and fell, he kept plugging along, never straying from who he is."

Lewandowski said he's one of the thinking voters: "I did my due diligence. I looked at the issues, especially the economy, but I also looked at how each candidate handled pressure and risk. I may love Newt Gingrich, but we need Mitt Romney."

Ryan Siedenburg, a high school senior, will turn 18 on Monday, making him eligible to vote.

"This is great," he said from the back of the crowded Machine Shed restaurant in Urbandale, while Texas Gov. Rick Perry made his pitch to Westside Christian Club breakfast attendees.

Perry portrayed himself as the authentic conservative and a Washington outsider.

"He may be," said Dave Siedenburg, Ryan's father, "but after much deliberation and a little prayer, I am going with Romney."

Salena Zito

Salena Zito is a political analyst, reporter and columnist.