In all, 57 different outside organizations spent at least $1 million in October. | REUTERS Outside groups spend $500M in Oct.

More than half a billion dollars.

That’s the monster mountain of money outside political groups collectively spent in October to fill the nation’s airwaves, scorch your phone lines and flood your mailbox with flyers that directly promote or attack federal candidates, according to a POLITICO analysis of federal campaign spending disclosures.


Leading the way were the Karl Rove-backed super PAC American Crossroads, its nonprofit sister group Crossroads GPS and pro-Mitt Romney super PAC Restore Our Future, which has been fueled by tens of millions of dollars from billionaires such as casino mogul Sheldon Adelson and Texas home builder Bob Perry.

The three groups together spent nearly $173 million last month on ads and other communications, with the bulk targeting President Barack Obama.

To put that in perspective: That’s nearly as much as the roughly $179 million that all outside together spent in September to promote or attack federal candidates.

Pro-Obama super PAC Priorities USA Action, bankrolled by the likes of billionaire investor George Soros and movie producers Steven Spielberg and Jeffrey Katzenberg, topped outside groups that support Democrats. Congressional races-focused super PACs House Majority PAC and Majority PAC followed closely behind. This Democrat-backing trio spent a combined $75.5 million in October.

In all, 57 different outside organizations — the majority of them conservative-leaning — spent at least $1 million in October to promote or attack federal political candidates.

All groups spent more than $526 million in total last month — a significant chunk of the $6 billion the Center for Responsive Politics predicts all federal-level candidates, parties and committees will spend during the 2012 election.

Among the organizations spending more than $5 million during October on independent expenditures — typically, ads or other mass communications that overtly support or oppose federal political candidates:

1) American Crossroads, $71.64 million, mostly in opposition to Obama and in support of Romney.

2) Restore Our Future, $51.64 million, all in opposition to Obama or in support of Romney.

3) Crossroads GPS, $49.36 million, mostly in support of Romney and several Republican congressional candidates and in opposition to Obama and numerous Democratic House and Senate candidates , most notably Sen. Sherrod Brown (Ohio), Rep. Shelley Berkley (Nev.), Tim Kaine (Va.), Tammy Baldwin (Wis.) and Joe Donnelly (Ind.).

4) Priorities USA Action, $31.47 million, all in opposition to Romney.

5) House Majority PAC, $25.29 million, mostly in opposition to numerous Republican House candidates, particularly Reps. Robert Dold (Ill.), Judy Biggert (Ill.), Jim Renacci and Michael Coffman (Colo.) and candidate Randy Altschuler (N.Y.).

6) Majority PAC, $21.73 million, mostly in opposition to Republican Senate candidates, particularly Tommy Thompson (Wis.), Linda McMahon (Conn.), Rep. Todd Akin (Mo.), Richard Mourdock (Ind.) and George Allen (Va.).

7) Service Employees International Union committees, $17.8 million, in support of Obama and numerous Democratic congressional candidates and in opposition to Romney and numerous Republican congressional candidates.

8) National Rifle Association committees, $15.4 million, mostly in support of Romney and numerous Republican congressional candidates and in opposition to Obama and numerous Democratic congressional candidates.

9) Americans for Tax Reform, $15.32 million, mostly against Democratic congressional candidates, particularly Rep. Bill Owens (N.Y.), Charlie Wilson (Ohio) and Al Lawson (Fla.).

10) U.S. Chamber of Commerce, $12.79 million, mostly in opposition to numerous Democratic congressional candidates including Senate candidate and Rep. Martin Heinrich, Brown and Baldwin.

11) FreedomWorks for America, $12 million, mostly in support of numerous Republican congressional candidates such as Rep. Jeff Flake (Ariz.) and Mourdock, and in opposition to numerous Democratic candidates including Tammy Duckworth (Ill.) and Sen. Bill Nelson (Fla.).

12) American Future Fund, $10.15 million, mostly in opposition to Obama and in support of Romney.

13) Congressional Leadership Fund, $7.94 million, all in opposition to Democratic congressional candidates, particularly Rep. Betty Sutton (Ohio), Brad Schneider (Ill.) and Pat Kreitlow (Wis.).

14) League of Conservation Voters committees, $7.68 million, mostly in support of Obama and numerous Democratic congressional candidates and in opposition to Romney and numerous Republican congressional candidates.

15) Independence USA PAC, $7.32 million, mostly in support of Democratic congressional candidates Val Demings (Fla.) and Gloria Negrete McLeod (Calif.) and Republican congressional candidates Andrew Roraback (Conn.) and Dold.

16) Ending Spending Action Fund, $7.25 million, mostly in support of Romney and Republican Senate candidates including Flake and in opposition to Obama and Democratic Senate candidates including Bob Kerrey (Neb.) and Brown.

17) American Federation of State, County and Municipal Employees committees, $7.01 million, mostly against Republican congressional candidates, particularly Flake, Thompson and Allen.

18) Americans for Job Security, $6.79 million, all against Obama.

19) EMILY’s List’s Women Vote!, $6.17 million, in opposition to numerous Republican congressional candidates, particularly Sen. Dean Heller (Nev.) and Thompson, and in support of several Democratic congressional candidates, most notably Baldwin and McLeod.

20) Planned Parenthood committees, $5.56 million, mostly in support of Obama and numerous Democratic congressional candidates and in opposition to Romney and numerous Republican congressional candidates.

21) Now or Never PAC, $5.33 million, mostly in opposition to several Democratic congressional candidates including Sen. Jon Tester (Mont.), Richard Carmona (Ariz.), Brown and Duckworth and in support of Akin.