If there were any doubts about how much the political landscape has changed post-Citizens United, here's one leading indicator: An analysis by Sunlight's Reporting Group shows that the biggest donors to super PACs are giving more political donations earlier in the campaign than they have in the past.

In the first 12 months of the 2012 election cycle, 37 individuals and 9 organizations each gave $500,000 or more to super PACs, for a total of $48 million. The same individuals and organizations gave a combined $64 million to a range of state and federal candidates during the previous four years.

These mega-donors, responsible for half the $95 million raised by super PACs as of Dec. 31, are, for the most part, seasoned campaign givers with histories of bankrolling organizations with political axes to grind. But a comparison with their current political giving with past cycles–when contribution limits were in place–demonstrates the dramatic effect of the rise of super PACs.

During the 2008 and 2010 campaign cycles, a four-year-period that included a wide-open presidential race and a hard-fought midterm congressional election, the same donors gave a combined $79 million, including some $15 million in donations to super PACs which first made an appearance in 2010. That figure, gleaned from data in the Sunlight Foundation's Influence Explorer and from the Center for Responsive Politics, includes all state and federal campaign contributions as well as donations to political non-profits organized under section 527 of the Internal Revenue Service, the precursors to today's super PACs, and to a handful of organizations that cropped up in 2010 as super PACs.

After the loosening of campaign finance laws in 2010 and super PACs began raising contributions in unlimited amounts, they have been flooded with cash from wealthy donors. Super PACs have made it possible for major donors with deep pockets to exercise their largesse more than ever, and data indicates that many are more willing to open their wallets wider than ever.

Super PACs spur more campaign contributions

Cases in point: Julian Robertson and Robert Mercer, two hedge fund managers, have each given $1 million to the pro-Romney super PAC Restore Our Future. That compares to the $397,000 for Mercer in the previous two elections to candidates and another $640,000 to super PACs in 2010 and $730,000 for Robertson.

Robertson, a New Yorker and founder of Tiger Management, one of the world’s leading hedge fund firms, has also dabbled in state politics — but well away from home. Campaign records show that he dropped $500,000 on the "No on 23 – Californians to stop dirty energy proposition" committee in 2010 — a successful campaign to maintain the Golden State's laws to roll back greenhouse gas emissions. That connection could be awkward for Romney, who has been accused of flip-flopping on environmental standards in order to win over the GOP's conservative base.

Another longtime donor who put the pedal to the metal after the Citizens United ruling: Robert Rowling, of TRT Holdings, owner of the Omni Hotel chain. His net worth is estimated at $4.7 billion. Based in Texas, Rowling has given $366,000 to Gov. Rick Perry’s statewide campaigns. Perry's appointment of Rowling to a post on the University of Texas Board of Regents sparked charges of cronyism.

In the 2008 and 2010 cycles, Rowling gave just over $1 million to various state and federal candidates and campaign committees, but topped it off with a whopping $2.5 million contribution American Crossroads, the political combine founded by GOP political strategists Karl Rove and Ed Gillespie in the summer of 2010, after Citizens United and another appellate court ruling lifted limits on contributions to independent political committees by wealthy donors.

So far this election cycle, Rowling has contributed $1 million to American Crossroads and another $43,300 at the federal level, including 30,800 to the National Republican Senatorial Committee.

Among the 9 organizations that have donated more than $500,000 to super PACs so far this cycle, Contran Corporation and Whiteco Industries are among the few whose 2011 super PAC giving did not exceed their total donations from the 2008 and 2010 election cycles. Contran has given $2 million to American Crossroads and $1 million to the pro-Rick Perry super PAC, Make Us Great Again. Company owner Harold Simmons has been a prolific contributor, both at the state and federal level. Whiteco, a real estate company based in Merillville, Ind., contributed $1million to the pro-Romney super PAC and has a history of donating to state and federal Republicans.

Contributions from labor groups such as the AFL-CIO, which has given $2.3 million to super PACs, will be analyzed in a future post. 

Big state donors debut on the national scene

Of the individuals who have given $500,000 or more in this election cycle, only a few have donated more in past political campaigns than they have so far for 2012. Some, like Bob Perry of the Texas-based real estate company Perry Homes, are long established players at the state level and have used super PAC giving to move to the national scene.

Perry, who has given a total of $3.5 million so far for 2012 races to Restore Our Future and American Crossroads — made headlines in 2010, the first year of super PACs' existence, by donating $7 million to American Crossroads. In addition, he contributed some $1.8 million to state and federal candidates and another $1.5 million to 527s during the last two election cycles. 

Donating to super PACs is in keeping with Perry's political giving patterns: Historically he has supported various organizations and 527s that have gone to bat for a candidate. In 2006 alone, Perry shelled out $10 million to give three groups, the Economic Freedom Fund, Americans for Honesty on Issues and the Free Enterprise Fund Commitee. In 2004, he was one of the chief contributors to Swift Boat Vets and POWs for Truth, the 527 that ran ads attacking the Vietnam war record of that year's Democratic presidential nominee, Sen. John Kerry of Massachusetts. The Swift Boat vets later got into trouble with the FEC for flouting laws against direct advocacy for a candidate and had to pay a $299,500 fine.

Such legal restrictions don't apply to super PACs, which have become magnets for donations from a wealthy few, recent campaign finance disclosures show. For example, January 2012 disclosures listing donor information shows that the the pro-Gingrich super PAC Winning Our Future which took in some $10.9 million, received almost all of its money from one source–casino kingpin Samuel Adelson and his wife. Adelson has hinted that more big donations could be coming. “I’m against very wealthy ­people attempting to or influencing elections,” he told a Forbes magazine reporter, “But as long as it’s doable I’m going to do it.”

Click here for a table showing top super PAC donors and their previous contributions.