An excerpt from The Gospel According to The Fix: An Insider’s Guide to a Less Than Holy World of Politics,”

to be published Tuesday.

You’ve probably never heard of Carl Forti. He has never been on television and he’s rarely quoted in the newspaper. But Forti knows the world of super PACs better than anyone in the Republican Party — and that knowledge makes him one of the most important strategists in the GOP heading into the fall election.

Before you get to know Forti, you need to get to know super PACs. Outside money has been spent on campaigns for as long as there have been campaigns. Wealthy individuals interested in politics have long sought ways around the relatively stringent federal campaign finance regulations — you can donate only $2,500 or so to a candidate — in hopes of exerting more influence on the electoral process.

In the early part of the 2000 campaign, the spending vehicle of choice was known as a 527, which referred to the section of the tax code that governed its operations. The groups could raise unlimited amounts of money from individuals, but they had to disclose the names and donation amounts of everyone who gave to them. The 527s also couldn’t directly advocate for the election or defeat of a candidate. What does that mean in real life? A 527 could run an ad highlighting John Kerry’s flip-flops on the war in Iraq. It couldn’t explicitly say that those flip-flops were a reason not to vote for him. It’s a subtle difference but an important one.

All of that changed in 2010 with the much-ballyhooed Citizens United ruling by the Supreme Court. Citizens United did lots of things to change campaign finance law in the country, but the most significant was that it got rid of the ban on outside groups expressly advocating for the election or defeat of a candidate. From that ruling came super PACs, political committees that are free to accept unlimited donations and directly advocate for or against a candidate. (Super PACs, like 527s, do have to disclose their donors and the amount of each contribution.) If Citizens United was the parent, the super PAC was the golden child. And Forti was the one who first recognized that the child was a political prodigy.

When I met Forti more than a decade ago, I would not have bet that he would become the man who would rock the political world. He was a big guy — a prototypical power forward in pickup hoops — who, in meetings, would almost always be sitting quietly in the corner with a smirk on his face. (If you looked up “palooka” in the dictionary, you got Forti.) In those days — circa 2000 — Forti was working as the communications director at the National Republican Congressional Committee, a job of considerable import in Washington. The NRCC is responsible for electing Republican candidates to the House — but with virtually no profile outside of Washington. (Little did I know what a talent incubator the NRCC was in those days; the political director, Terry Nelson, went on to manage Sen. John McCain’s 2008 presidential campaign.)

Forti stayed with the NRCC for four elections. By the 2006 elections, he was not just managing the communications operation but was also running a vast independent expenditure program — under another quirk of campaign finance law, the party committees could run television ads in hopes of influencing the outcomes — that eventually spent more than $80 million. (All of that spending did Forti — and the GOP — little good in the 2006 election; Democrats won back the House after 12 years in the wilderness of the minority.) He left that gig to move to Boston to serve as the political director of Mitt Romney’s 2008 presidential campaign. “Why would you want to talk to me?” Forti remembers asking the Romney team, noting that all of his experience was on the communications side, not the political side. The response? “You get [expletive] done.”

When Romney went kaput in the presidential race, Forti moved back to Virginia and started a consulting business known as the Black Rock Group. (The firm was named after Black Rock, N.Y. — a neighbor to Forti’s native Buffalo.) And that’s when things started happening for Forti in the world of super PACs.

American Crossroads

It all began with American Crossroads, a super PAC organized around the 2010 election and designed to help Republicans win House and Senate seats. George W. Bush administration political svengali Karl Rove and longtime Republican operative Steve Law were the two other foundational pillars of Crossroads. (They raised the money, he spent it, Forti explained.) American Crossroads grew into a fundraising behemoth and a Democratic nightmare.

For the 2010 election, Crossroads raised and spent $71 million on House and Senate races, a massive sum that helped tip control of the lower chamber to Republicans and aided the party’s six-seat pickup in the Senate. And Crossroads didn’t let up, raising $51 million in 2011 and doubling — yes, doubling — its initial $100 million fundraising goal for 2012 to $200 million.

Even as Crossroads was taking off, Forti as well as a few other Romney loyalists formed a super PAC known as Restore Our Future, designed to help the former Massachusetts governor win the Republican presidential nomination. And help him it did. Restore Our Future collected $30 million in 2011 alone and used those millions on an all-out assault on Newt Gingrich that blunted the momentum the former House speaker was building in late 2011 and early 2012 and allowed Romney to secure much-needed victories in New Hampshire, Florida and Nevada.

As of early March 2012, 371 super PACs had raised more than $130 million for the 2012 campaign. The mightiest were those affiliated with Republican presidential candidates. Restore Our Future led the way, with $34 million collected, followed by Winning Our Future, a super PAC aligned with Gingrich that raised $16 million — almost all of which came from the personal checkbook of casino magnate Sheldon Adelson.

Adelson’s largess directed to Gingrich is evidence of just how much super PACs have changed the political calculus in the less than two years they have been in existence. During the 2008 contest, a candidate like Gingrich, who has experienced very little success raising money for his official campaign account, would have been forced out of the presidential race months ago — unable to pay his staff, travel the country or run television ads.

But in the new super-PAC world, Gingrich needed to convince only one very rich person — Adelson — of his continued viability in the race. Beginning in January, Adelson has cut a series of multimillion-dollar checks to Winning Our Future, which is run by — surprise, surprise — a longtime Gingrich staffer named Rick Tyler. Those donations paid for thousands of television ads in South Carolina, a state Gingrich won in the GOP primary in late January, and helped him secure a victory in his home state of Georgia on March 6.

Without Adelson, Gingrich would have been an afterthought in the 2012 presidential race. With him, Gingrich remained a viable candidate all the way through mid-March. That’s how drastically super PACs have changed the field on which the presidential race is being fought.

Obama’s response

The White House was paying close attention to the tens of millions of dollars pouring into Republican super PACs in the first few months of 2012. And it was getting worried. So in February, the White House reversed its stated opposition to such groups. In an e-mail sent to supporters, Obama campaign manager Jim Messina argued that the move was born of necessity: “We decided to do this because we can’t afford for the work you’re doing in your communities, and the grassroots donations you give to support it, to be destroyed by hundreds of millions of dollars in negative ads,” he wrote.

The Obama political team made a very simple political calculation. It could reverse course, take the near-term hit from campaign finance reform advocates and reap the long-term financial benefits, or stay the course and run the risk of being outspent in 2012. Viewed that way, the decision was a no-brainer and had echoes of President Obama’s decision in 2008 to go back on his promise to abide by public financing once it became clear that he could dramatically outraise McCain in the fall campaign. His Republican critics lambaste Obama as an ideologue, but decisions such as the one on super PACs make clear that he is, at heart, a political pragmatist. Which, of course, is why he’s president.

What secret has Forti figured out that inspires such fear in the White House? He insists that there is no secret, and if he knows one, he certainly isn’t telling. He attributes his success to “keeping my head down and doing my job,” adding: “I’m not a self-promoter. I’m not on TV all the time.” (What’s wrong with being on TV all the time? But I digress.)

Forti’s preference to be behind the scenes rather than in front of the camera may be key to understanding why he has been affiliated with the two most successful super PACs on record. These organizations function on privacy; donors are the most skittish of political animals and need to know that the people they are dealing with can keep a secret. (Donors also want to know that their money is being well spent or they will stop giving, Forti said. “You can’t convince these folks to give the type of money they are giving if they don’t think they are having an impact,” he added.) Forti’s great gift then is his discretion. He is a vault, and donors — and the staffers he works with — know it. That’s why they tell him things. And that’s why he’s the super PAC whisperer.

Cillizza writes The Fix, a political blog for The Post.

The Gospel According to The Fix:

An Insider’s Guide to a Less Than Holy World of Politics

By Chris Cillizza.

Broadway, 224 pp.

Paperback, $11.99.