(CNN) -- If Wisconsin Gov. Scott Walker wins Tuesday's recall election, the big bucks the Republican governor and his allies have spent to run TV commercials will be a contributing factor.
Walker, the Republican Governors Association, and independent tea party groups and other grassroots fiscal conservative organizations have spent around $2.484 million to run ads in the recall campaign over the past week, according to data provided to its clients by Kantar Media/Campaign Media Analysis Group, a company that tracks and estimates the costs of campaign television ads.
That's more than double the $1.125 million Milwaukee Mayor Tom Barrett, Walker's Democratic challenger, Democratic Party committees and independent progressive groups have spent to run commercials from last Monday through Sunday. Overall nearly $3.6 million has been spent to flood Wisconsin airwaves with recall spots the past week.
"In a competitive election, to see one side have an advantage in ad spending is unusual. So we are not only in unchartered waters because it's a recall contest, we're in unchartered waters because of the volume of political advertising," said Kenneth Goldstein, CNN's consultant on TV advertising and Kantar Media/CMAG president.
"There was talk that the advantage Gov. Walker and his Republican allies enjoyed in terms of ad spending would diminish in the final weeks of this campaign, but that hasn't happened," added Goldstein, who's also a longtime professor of political science at the University of Wisconsin-Madison.
The Republican advantage in ad spending is not just a one-week phenomenon. Dating back to November 1, Walker and his Republican allies have spent $12.3 million to run ads, more than double the $5.6 million spent by Barrett and his Democratic allies. Overall, more than $18 million has been shelled out to run recall related spots since the beginning of November.
"The spending advantage isn't just about Republicans out-advertising Democrats -- especially now, given the law of diminishing returns for TV ads. It's about how Walker and the GOP used the advantage along the way, shoring up Walker's standing with independents early on, and pounding Barrett so hard that he got no bounce out of his primary win," Kantar Media/CMAG Vice President Elizabeth Wilner told CNN. "With the race tightening, if Walker pulls it out, it will have a lot to do with those early investments."
The most recent non-partisan public opinion polls indicate Walker with a slight single-digit advantage over Barrett.
Walker set off a firestorm in January 2011 when he moved to curtail the collective bargaining rights of most Wisconsin state employees.
With majorities in both houses of the legislature, Walker and his GOP allies voted to limit raises for public employees except police and firefighters to the rate of inflation, bar unions from deducting dues from workers' paychecks and force them to hold a new certification vote every year. That bill was signed into law in March, following weeks of protests at the state capitol building in Madison.
Republicans insisted it was necessary to control the skyrocketing costs of public employee benefits and close the budget shortfall. Democrats argued it was an attempt to gut public-sector labor unions, one of their core constituencies.
The public demonstrations all but shut down the Wisconsin state legislature for weeks. It also drew protesters by the tens of thousands, among them union supporters and public employees, who called the measure an attack on workers. A group of Democratic lawmakers left the state for some time in an effort to not allow a quorum for a vote.
The state Supreme Court upheld the controversial law in June, but the battle sparked a storm of political activism that led to the recall effort. The election was scheduled earlier this year, after more than 900,000 signatures petitioning for a recall of the first-term governor were collected.
This would be the first time in Wisconsin's history that a governor has faced recall. There have only been two successful gubernatorial recalls in the nation's history: California Gov. Gray Davis in 2003 and North Dakota Gov. Lynn Frazier in 1921.
Republican Lt. Governor Rebecca Kleefisch and four GOP state senators also face recall elections Tuesday.
Regardless of whether history is made Tuesday in the recall election, Wisconsin is on track to make some other history.
"This advertising campaign in the governor recall contest is just a small fraction of what Wisconsin residents have seen and will see this year," says Goldstein. "Thanks to advertising in the GOP primary for president, the recall election primary and general election, the Republican Senate primary and competitive races for U.S. Senate and president in the fall, Wisconsin is on track to have the largest number of political ads ever aired in a state."