Four years ago, Iowa was awash in presidential candidates crisscrossing the state. Campaign headquarters were packed with staffers and volunteers. The airwaves were clogged with political commercials. Excitement was palpable. Today, everything seems different.

Iowa still holds its coveted position as the state whose caucuses will mark the opening of the Republican presidential nomination process. What happens here Jan. 3 will still have a major impact on the Republican race. But at least for this presidential cycle, Iowa has lost much of the unique character that has marked previous campaigns.

Candidates are spending less time and money here. They have held fewer events, and those events (with a few exceptions) draw smaller audiences and generate less excitement than in the past. Campaign organizing is months behind the pace of the past several cycles. Advertising has only just begun in earnest.

In past elections, Iowa voters often saw things before voters elsewhere — because they had an early opportunity to examine the candidates repeatedly and close up. They discovered Jimmy Carter in 1976 when he was unknown. They launched President Obama in 2008 when Hillary Rodham Clinton was ahead in the national polls. They saw Mike Huckabee’s potential four years ago earlier than voters elsewhere.

This year they are moving less independently. As Republican voters have shifted nationally, Iowa voters have changed with them, from Rep. Michele Bachmann (Minn.) to Texas Gov. Rick Perry to businessman Herman Cain and now to former House speaker Newt Gingrich. “There’s much more of a national presence and much less of a local footprint in the state,” said J. Ann Selzer, an Iowa-based pollster.

Saturday’s Republican debate in Des Moines began a three-week sprint to the finish in Iowa, and the pace is beginning to quicken. Republicans will debate again Thursday night in Sioux City. Candidates are promising to be back here often before Jan. 3. But the anticipated activity only serves to draw attention to how dissimilar this campaign has been to date from those in the recent past.

“We have this different dynamic with the debates, cable covering the campaign wall to wall, the Internet, [newspapers] updating throughout the day, blogs, tweets, everything going on,” said Dave Oman, a veteran Republican activist who is backing Mitt Romney this year. “So it wouldn’t surprise me that we are responding to all of what’s going on and communicating it similar to the rest of the country.”

What’s not clear is whether this year’s campaign in Iowa is an anomaly or a look into the future. That’s part of the discussion among politically active people in the state this fall. A few weeks ago, Gov. Terry Branstad upbraided Romney for not spending enough time here. Is he worried that the absence of activity will diminish Iowa’s role in the future?

“We always worry about that,” Branstad said with a laugh. “It’s one of those things. We worry about that just like we worry about the price of corn. Right now the price of corn is real good but we always worry that it’s not going to stay there.”

Matt Strawn, the Iowa Republican Party chairman, isn’t prepared to say whether this year’s campaign is a new normal in Iowa, but he worries about the consequences if it is. “If we get away from a process that demands candidates who want to be president of the United States actually let regular American citizens look them in the eye and ask questions, well then it’s a slippery slope toward a national primary, and in my view all a national primary is, is a fundraising contest,” he said. “So I think the process would suffer if this new normal is going toward a more nationalized campaign and primary season.”

The differences in this year’s campaign are not hard to find. Stop by any of the candidates’ campaign offices that dot the Des Moines area, and the silence is deafening. At the Bachmann headquarters early last week, only a few people were making calls. At Gingrich’s newly opened office, the most striking visual was scores of cellphones plugged into outlets in an otherwise mostly empty space.

Looks can be deceiving, say strategists who are helping organize for the caucuses. With the advent of cellphones, social media and other new technology, much of what was done in the headquarters is now done out of sight, in people’s homes — whether in Iowa or nationally into Iowa.

“Years past, you and I are used to the headquarters with rows and rows of phones,” said Eric Woolson, Bachmann’s Iowa campaign manager. “So much of this is personalized, do-this-at-home now. People can get on the computer. A call list comes up. The number comes up. They actually dial it through their computer.”

But veterans of past campaigns say there is a palpable difference in the intensity of organizing. “There’s less of the great organizations that I watched being built during the Bush-Forbes campaigns or the Bush-Dole campaigns,” said Steve Grubbs, who was a senior adviser to Cain’s campaign. He was referring to the 2000 campaign that pitted George W. Bush against Steve Forbes and the 1988 campaign in which Bob Dole and George H.W. Bush went head to head here.

Bachmann and Rick Santorum have approached Iowa the old-fashioned way this year and have little to show for it. Santorum has visited all 99 Iowa counties. Bachmann won the Iowa straw poll and has worked to build an organization. The two are badly trailing in the polls here.

One exception is Ron Paul, who has a highly rated organization and whose standing in the polls has risen to the point that he is a major factor in the race here.

The organizational duels that marked previous campaigns are missing this year because no one appears worried that they are far behind another candidate. Finding county chairs in the 99 counties has been a struggle for some candidates, let alone finding precinct leaders for the more than 1,774 precincts that will hold caucuses next month.

“Most campaigns, given the fluidity of this cycle, have tried to be a little bit more strategic, so you’re going to rank order your counties, you’re going to rank order your precincts and you’re going to make sure you’ve got coverage in the really important ones,” said Bob Haus, Perry’s Iowa chairman.

Nor has television advertising proven effective — at least so far. Perry has run more ads than any campaign here but has not been able to bounce back from the damage inflicted on his candidacy from debates in September and October.

For some Iowans, particularly younger voters or first-time activists, a campaign waged more on television than in coffee shops may suit them just fine. For veteran activists, who are used to having the chance to meet candidates one-on-one when they come to town, the changes have been less satisfying. “We’ve lost that this cycle, and I hope we can get back to that because I do think the process is better served by that retail interaction,” Strawn said.

If Iowans feel they’re not getting the love from the candidates they got in the past, they can look forward to Jan. 3. Being first to hold a vote still counts. “The meaning of the caucus that you cannot deny and will not change is it’s the first opportunity for a candidate to win,” Selzer said. “And winning is the most important thing a candidate can do . . . and the other states look to that. It does have an influence.”