After a slow start, the Republican presidential hopefuls and the political action committees that support them are saturating Iowa TV with mostly negative ads.
Spending on campaign ads has reached nearly $6 million in the run-up to the state's Jan. 2 nominating caucuses.
"The race is fully engaged now," said Ken Goldstein, president of Campaign Media Analyst Group, which tracks political advertising spending.
In the 2008 campaign cycle, between $37 million and $42 million was spent on political advertising in Iowa.
But Mr. Goldstein believes the slew of GOP debates and "dramas" such as the harassment allegations against Herman Cain prompted campaigns this year to hold off on advertising in Iowa.
The lack of a contest on the Democratic side will also result in less spending in Iowa than four years ago, Mr. Goldstein said.
While campaigns are spending less, independent groups have ratcheted up their involvement.
According to the Federal Election Commission, Restore our Future -- a "super PAC" created to support Mitt Romney -- has bought $2.6 million worth of ads attacking Newt Gingrich.
Mr. Romney's campaign is spending about $1 million in ad buys in Iowa.
But Texas Gov. Rick Perry is the biggest spender in Iowa, buying more than $500,000 worth a week in December.
In addition, the super PAC Make Us Great Again has spent $2.9 million in advertising in support of the Texas governor, whose feeble showing in Iowa polls strengthened after the barrage of advertising began this month.
Steve Lake, national sales manager for KCRG, an ABC affiliate in Cedar Rapids, Iowa, said all major candidates and their PACs have bought time on his station, but the amount is "less than four years ago by a lot."
"Still there are so many ads now, and they change so often, it's hard to remember them all," Mr. Lake said.
While campaigning in Iowa has been largely negative, with Mr. Gingrich the chief target , the campaigns toned down their message on Christmas Eve and Christmas Day.
Mr. Gingrich, Mr. Perry and Mr. Romney included their wives in the warm and fuzzy holiday spots. "But on December 26, they were right back on it," Mr. Lake said.
Uncharacteristically for the pugnacious former House Speaker, Mr. Gingrich has adopted a largely positive ad strategy in Iowa, where his campaign has bought about $250,000 worth of air time.
But Mr. Gingrich's super PAC, Winning Our Future, has budgeted more than $1 million to spend in Iowa and a spokesman has not ruled out last-minute attack ads.
Rep. Ron Paul of Texas, who ran the first TV ad in Iowa, continues to spend money to stay on the air. According to published reports, his campaign bought 1,423 ad spots for $728,030 in December for the markets in Des Moines, Cedar Rapids and the Quad Cities -- five cities straddling the Mississippi River on the Iowa-Illinois border.
Outside groups are also making a last-minute plunge into the race in Iowa.
Citizens United, a group linked to GOP strategist Karl Rove, paid $250,000 to run an ad promoting a Ronald Regan documentary featuring Mr. Gingrich.
Mr. Lake said his station is running that ad and expects other outside groups to make end-of -the-year buys.
With many caucus voters undecided, there could be a big payoff for last-minute adverting in Iowa. "It's a wide open race," said CMAG's Mr. Goldstein.