Washington, D.C. (AP) - Look no further than Iowa to understand the impact of a Supreme Court ruling that opened the floodgates to outside money in American politics - and to get a glimpse of what's in store for the race between President Barack Obama and the eventual Republican nominee.
Independent groups called super political action committees have spent millions on television ads and mailings to boost their favored candidates in Iowa and maim those candidates' rivals, dramatically influencing what's been a remarkably fluid race for the GOP presidential nomination.
The groups have ramped up spending just as the primary season is hitting full-force. Some have done the campaigns' bidding by running attack ads on rivals. Others have bolstered candidates who had been running on financial fumes.
The trend will hardly be unique to Iowa. Political operatives and campaign-finance watchdogs say the 2012 election - projected to be among the costliest ever - will face an onslaught of ads by powerful interests that will have an extraordinary say in who might next occupy the Oval Office.
With more than 300 days to go before the general election, the measures of influence are legion: Some TV ads assail Newt Gingrich for "collecting big bucks" from mortgage lender Freddie Mac, and others praise Mitt Romney for "turning around" dozens of companies. One heralded Rick Santorum as a "courageous reformer with results" while another credited Rick Perry for his outside-the-Beltway experience.
Meanwhile, the candidates didn't have to spend a dime of their own money for any of those ads.
"We're going to see huge amounts of money in the course of 2012 spent by the candidate-specific super PACs," said Fred Wertheimer, president of the watchdog group Democracy 21 and a prominent critic of the new groups. "They are vehicles for big donors to circumvent the contribution limits and give money that directly benefits the candidates."
In just one week before the election's first vote, groups like the Romney-leaning super PAC Restore Our Future and the Perry-leaning Make Us Great Again have spent a combined $1.2 million on television ads in Iowa - a sum greater than what the candidates paid out themselves. On top of that, experts say the ads this primary season are more negative than they were four years ago.
The super PACs are a product of the 2010 Citizens United ruling by the Supreme Court, which removed restrictions on corporate and union spending in elections. Still, Republican-leaning groups far outpaced their Democratic counterparts in that year's midterm elections, helping Republicans win control of the House and pick up six seats in the Senate.
Nearly two years later, the money is still flowing to GOP candidates.
Take the Gingrich-supportive Winning Our Future super PAC, which is boosting the former House speaker's once-struggling campaign that a few months ago reported $1 million in debt. The group footed the bill in Iowa for more than $191,000 in ads last week supporting Gingrich, whose candidacy surged in December. His campaign spent only a fifth of that amount during the same period.
The group is hardly alone: Since Christmas Day, the Romney-leaning Restore Our Future spent nearly $130,000 on direct-mail ads and at least $1.2 million on ads supporting the former Massachusetts governor while also hammering Perry, federal data show.
And Endorse Liberty, a super PAC supporting Texas Rep. Ron Paul, put much of its money into the web and social media. It spent at least $100,000 on Google's AdWords service and about $40,000 on Facebook commercials during the same period.
For their part, super PAC operatives make no apologies for what they say is legally protected free speech. They have been upfront about their motives: Groups like the Karl Rove-backed American Crossroads have promised to spend tens of millions in the general election to defeat Obama. On the other side of the aisle, former Obama aide Bill Burton runs the super PAC Priorities USA Action, joining a handful of similar Democratic-oriented super groups.
Some GOP-leaning groups say their ads contribute to a marketplace of ideas, counterbalancing the huge sums of cash that Obama and the Democratic National Committee plan to spend on the president's re-election bid. Democrats say they have to push back forcefully against attacks on Obama's record.
By law, presidential campaigns can raise at most $5,000 total from an individual donor. But super PACs can solicit and spend unlimited money. Some employ affiliated groups whose donors are allowed to remain anonymous.
The super PACs can't, however, coordinate directly with candidates but many of the super PACs active in this election are staffed by longtime supporters of the candidates.
Looking ahead past the Iowa caucuses, the groups' impact is set to remain strong: Make Us Great Again, a super PAC that supports Perry's candidacy, recently booked at least $130,000 for TV spots for this week in South Carolina, which holds its critical primary on Jan. 21. At the time, Perry's campaign had yet to spend a dollar on similar ads.