More than $200 million in outside money has poured into Florida elections since a landmark 2010 U.S. Supreme Court decision, bombarding voters with ads, weakening control candidates have over their own messages and pitting free speech rights against increasing secrecy.

Florida is one of the biggest and most expensive laboratories in this new era of loosely regulated money raised and spent beyond candidate campaigns, and the Tampa Bay Times' review is the first attempt to grasp the sheer volume and reach in federal elections.

Some 170 outside groups, many that did not exist before 2010, are reshaping the Florida landscape, or at least turning up the noise with an overwhelmingly negative stream of TV and radio ads, mailers and phone calls.

"It's an X-factor," said Alex Patton, a Republican consultant in Gainesville. "You don't know when it's coming, how it's coming or what it's going to say."

The $200 million estimate comes from research the Center for Responsive Politics provided to the Times, Federal Election Commission records and interviews with officials at some of the biggest independent groups. The total does not include the millions spent by candidates themselves.

Florida is among the top states where the outside money has flowed because it is an important presidential battleground and has had a string of competitive congressional elections. A court decision this month forcing the Legislature to redraw U.S. House districts could widen the playing field.

"This is emblematic of the hydraulic theory of money in politics. If there's an opportunity, the money will flow," said Sheila Krumholz, executive director of the Center for Responsive Politics.

Arriving at a hard number is virtually impossible due to uneven disclosure requirements. "Issue" ads that do not expressly advocate for or against a candidate are not subject to FEC reporting as long as they are outside a certain window for an election — and they have been plentiful. And, groups that spent tens of millions in the presidential race were not required to flag Florida ad buys.

Nonetheless, the figures are startling.

Outside spending in Florida U.S. House and Senate races reached $6.8 million in 2008. By 2010, after the Supreme Court opened the floodgates, it had jumped to $21 million. In 2012, it was $52 million.

Collectively, outside groups have spent more than $85 million in congressional races in the past four years, including $9 million poured this spring into the battle for the Pinellas County seat held for decades by the late Rep. C.W. Bill Young.

Outside money in that contest was about $4 million more than the candidates spent combined, a feat that could be replicated in tight races across the country in the months and years to come.

"I joke that Alex (Sink) and I could have gone on vacation the last two weeks and nobody would have known because the amount of outside messaging was so overwhelming," said Rep. David Jolly, referring to his Democratic opponent. "I was drowned out not just by the other side but my own team."

The Congressional District 13 contest is a case study of the new order. More than 20 outside groups got involved, including super PACs and political nonprofits that have risen as a result of the Supreme Court ruling.

The 5-4 Citizens United decision said corporations and unions had the right to make unlimited political contributions in support or opposition of a candidate. Corporations aren't rushing to get involved, tending to prefer traditional political action committees, but some of the wealthiest people in the country are, a relative handful now effectively unbound by campaign finance limits.

Other court decisions and campaign finance laws have contributed, but the Citizens result has been unprecedented sums injected into elections across the country. It's as far flung as Alaska, where $20 million in ads are expected in this year's U.S. Senate race, one of several that could decide which party controls the chamber. And it's as local as school board elections in New Jersey and Los Angeles, a mayoral contest in Boston and a race for constable in Texas.

As the tentacles stretch, so does the debate over where it is all headed.

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Overall in Florida, conservative groups have outpaced liberals since 2010. Of the $85 million in congressional races, 60 percent came from Republican-minded organizations.

"The increase in outside money has leveled the playing field and allowed conservative candidates to compete with what used to be an overwhelming amount of labor union and trial lawyer-funded resources," said Charlie Spies, who ran the pro-Mitt Romney group Restore Our Future.

In 2012, his super PAC spent at least $24.5 million on TV ads in Florida (and $153 million nationally), second only to American Crossroads and Crossroads GPS. The Crossroads groups, founded by GOP strategist Karl Rove, unleashed at least $37.5 million in Florida on the presidential race.

U.S. Sen. Bill Nelson, an Orlando Democrat who ran for re-election in 2012, faced an onslaught of $22 million from Crossroads and other right-leaning groups, more than double the amount spent by Democratic-aligned groups that came to his defense.

Nelson partly attributes his victory over former Rep. Connie Mack to an ability to raise enough of his own money to fend off attacks, which focused on his support for the Affordable Care Act and other policies of President Barack Obama.

"You're doggone right I was concerned," said Nelson.

For a dramatic example, take Las Vegas casino magnate Sheldon Adelson. Had he given directly to Mack's campaign, he would have been limited to $2,500 each for the primary and general election. But Adelson faced no restriction in donating to the pro-Mack group Freedom PAC — and ponied up $2 million.

Former New York Mayor Michael Bloomberg, a billionaire like Adelson, started his own super PAC and spread millions across the country, including $2 million in support of Val Demings, a pro-gun control Democrat who challenged Orlando-area Rep. Dan Webster in 2012. Demings, like Mack, lost.

Defeats like those have not stymied outside spending. And more of it is coming from sources hidden from public view. Super PACs such as Restore Our Future must disclose donors, but a booming breed of "social welfare" and business trade groups such as the U.S. Chamber of Commerce do not.

When Nelson ran in 2004, only $3,715 in such money emerged in the race, according to the Center for Responsive Politics. In 2012, it was nearly $4.7 million.

"Free speech is not constitutional when you yell 'fire' in a crowded theater," Nelson said. "Why should unlimited money be allowed to perpetuate untruths and that money not be identified?"

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Nelson has vowed to use his clout as the next chairman of the Commerce Committee to push for more disclosure of so-called dark money.

But Nelson can only pursue that goal, which would meet certain resistance in the GOP-held House, if Democrats keep the Senate. And outside money could decide key races across the country, including Alaska, Arkansas, Colorado and North Carolina.

One group, Americans for Prosperity, plans to spend $125 million on the midterm elections.

Americans for Prosperity, a major player in Florida, has drawn fire for not revealing the source of its funds, though billionaire industrialists Charles and David Koch started the group. The Koch Brothers have been demonized by Democrats at the same time liberal groups are racing to play the same game.

"I have many clients who would prefer a world where money did not have so much influence," said Bill Phillips, a Democratic consultant in Florida who advises major donors and started his own super PAC. "My message to them is the court has ruled. Money is speech. This is an opportunity to have a voice. If you want to fight for a more level playing field, it's going to be about transparency."

Tim Phillips, AFP's president, said donors could be subjected to harassment if disclosed and argued there are still checks and balances. "If a group gets out there and overdoes it, the public will look at them askew," he said in an interview from Arlington, Va., where the group is headquartered.

Jolly, who got help from Americans for Prosperity and other groups, said he supports free political speech but lamented how outside money controlled the campaign message. His race with Sink was waged largely on national terms, a debate over Obamacare and Medicare, drowning out what the candidates would do for the district.

"We have to do better and frankly, the voters deserve better," said Jolly, who supports calls for more disclosure.

The lack of accountability leads to more negative ads but also gives the groups a certain credibility, said Krumholz of the Center for Responsive Politics.

"Voters can't put them in the box and say, 'That's Planned Parenthood, I know how I feel about them. That's the NRA.' Instead it's Americans for America. Voters take the extra time to hear their message and, ironically, absorb it and give them credibility that they may not be due."

Spies, who set up Restore Our Future, said an ideal fix would be to allow unlimited donations to candidates with the donors disclosed immediately. "You would have candidates that have to take responsibility for their message.

"Absent that," he added, "it is important that all viewpoints have an ability to be communicated."

Contact Alex Leary at aleary@tampabay.com. Follow @learyreports.